[HN Gopher] A story about bypassing air Canada's in-flight netwo...
       ___________________________________________________________________
        
       A story about bypassing air Canada's in-flight network restrictions
        
       Author : samray
       Score  : 165 points
       Date   : 2025-10-10 07:50 UTC (15 hours ago)
        
 (HTM) web link (ramsayleung.github.io)
 (TXT) w3m dump (ramsayleung.github.io)
        
       | 4rt wrote:
       | tldr; the wifi's access restrictions still allowed DNS so they
       | set up a vpn on the dns port
        
         | technothrasher wrote:
         | I remember doing this about twenty years ago when many hotels
         | blocked the internet behind a paywall but were naive in their
         | approaches. I also remember trying this at a hotel in Tokyo
         | about ten years ago and instantly finding my MAC address
         | blacklisted. Their networking folks were clearly more
         | sophisticated.
        
       | roygbiv2 wrote:
       | Iodine has done this for many years.
       | https://github.com/yarrick/iodine
        
         | BehindTheMath wrote:
         | I haven't used iodine, but this seems simpler. Iodine wraps
         | requests with actual DNS requests. In this case that wasn't
         | needed, because port 53 wasn't filtered at all. So all they
         | needed was a simple proxy on port 53.
        
           | krautsauer wrote:
           | iodine automatically checks several modes a "simple" proxy on
           | port 53 being one of them. If you're trying to sneak traffic
           | through this kind of block, it is really the first tool to
           | try.
        
         | kangs wrote:
         | Dan Kaminski popularized this in 2007-8 or so. Not that it
         | didn't exist here and there, but he made the perhaps first
         | public version of a dns tunnel (ozyman). he inspired iodine and
         | others and was a fairly well known guy.
         | 
         | Dan passed away in 2021, rip.
         | 
         | if you search for it its hard to find. his blog is down (hea
         | dead...), and many companies and people talked about it on his
         | behalf to drive traffic (hi duo sec..), so you can see the
         | internet forget, rediscover, and rewrite some history even in a
         | few years.
        
         | DaSHacka wrote:
         | Yeah, I was gonna say I've used Iodine to get free Wi-Fi on
         | Delta flights for years at this point.
        
       | traceroute66 wrote:
       | > We affirm our strict adherence to all relevant regulations and
       | service terms throughout this project.
       | 
       | Except if you bypassed payment and used the service in a manner
       | that was not intended, most likely you were by definition not
       | undertaking "strict adherance" to service terms ?
        
         | VladVladikoff wrote:
         | Yeah I am a bit confused about posts like this. It's bragging
         | about breaking the law. There was a particularly bad one a few
         | months ago where a kid had hacked Monster's employee training
         | site, and was sharing all this internal media in the post. I
         | don't understand how they don't end up getting in some
         | seriously annoying trouble with law enforcement. Well I looked
         | it up just now and the post was deleted, I guess maybe he did
         | get in trouble. https://news.ycombinator.com/item?id=44997145
        
           | CaptainOfCoit wrote:
           | Could also just be lack of knowledge. Weren't we all a bit
           | more risky and playful with other people's websites when we
           | were kids and the internet was still accessed via modems?
           | Remember talking about that with both other kids and adults
           | without getting in trouble, but it was also decades ago. Once
           | I saw others getting in real big trouble (like prison), then
           | I kind of tried to find more beneficial ways of learning
           | programming and computers.
        
             | traceroute66 wrote:
             | > Could also just be lack of knowledge.
             | 
             | Huh ?
             | 
             | DNS tunneling is not exaclty something you do "by
             | accident".
             | 
             | And if the person doing it on the flight "did not know"
             | (which, given the text of the blog, I doubt) , then you can
             | bet your botom dollar that the "roommate" that was summoned
             | for remote assistance knew very well what was going on.
        
               | CaptainOfCoit wrote:
               | Didn't claim so either, but a lack of knowledge about
               | that it is in fact illegal, hence the parallel to at
               | least my previous experience where I've most surely have
               | committed crimes in the past, because I didn't know it
               | was illegal in the first place.
               | 
               | I don't know the age of the author, but it almost doesn't
               | matter, sometimes people don't know (lack of knowledge).
        
               | anigbrowl wrote:
               | Come on now. $31 for inflight wifi is a ripoff, but even
               | a 6 year old understands that if there's a price tag it's
               | not an invitation to help yourself.
        
             | gus_massa wrote:
             | > _Remember talking about that with both other kids and
             | adults without getting in trouble._
             | 
             | A few kids doesnt matter. A few adults is only a problem if
             | it's their stuff (If they are teachers, they will care more
             | about unautorized changes of the wallpaper in the computer
             | of the school that anything in a remote computer.) And yuo
             | can even later claim they misunderstood or you were
             | exagerating.
             | 
             | But here is an in written report in front of thousands of
             | persons and about planes that is a sensitive topic.
        
           | eps wrote:
           | > breaking the law
           | 
           | Not law per se. More like contractual obligations taken upon
           | by connecting to the flight's WiFi.
        
             | traceroute66 wrote:
             | > Not law per se. More like contractual obligations taken
             | upon by connecting to the flight's WiFi.
             | 
             | Well, being pedantic, you could be said to be breaking
             | Civil Law. :)
             | 
             | Jest aside, IANAL but most western countries have some sort
             | of Criminal Law relating to mis-use of computers.
             | 
             | A brief search for Canada reveals Criminal Code (R.S.C.,
             | 1985, c. C-46)[1].
             | 
             | Again IANAL, but from my reading in this scenario it would
             | be (c) -> (a), "uses or causes to be used ... a computer
             | system" to "obtains, directly or indirectly, any computer
             | service".
             | 
             | [1]https://laws-
             | lois.justice.gc.ca/eng/acts/C-46/section-342.1....
        
             | gruez wrote:
             | Isn't this pretty straightforwardly "theft of service",
             | like "stealing" cable TV service?
        
             | Aurornis wrote:
             | Most countries will have laws covering cases of
             | unauthorized access, theft of services, and computer
             | misuse.
             | 
             | The user agreement helps define the service as a paid
             | service with defined access cases. Going around those would
             | put the user in violation of some laws.
             | 
             | An analogy would be showing up to a paid event venue and
             | noticing a back door was left open. Going into the building
             | without paying is not okay, even though you never engaged
             | with the ticket office to agree to anything.
        
               | ballenf wrote:
               | If the user routed all traffic through a WeChat or other
               | messaging service, they would just be using messaging.
        
               | nradov wrote:
               | Intent matters. In US legal jurisdictions that could
               | potentially be prosecuted as a CFAA violation, although
               | I'm not aware of any cases like that yet.
               | 
               | https://www.justice.gov/jm/jm-9-48000-computer-fraud
        
               | DaSHacka wrote:
               | The U.S. has one of the most overbearing laws in that
               | regard, though. The OP happened on a flight leaving
               | Canada.
        
               | zem wrote:
               | I would have had far more positive feelings towards the
               | hack if they had done that - e.g. had their roommate
               | configure a bot to monitor a wechat room and respond to
               | url requests by sending back a webpage. tunneling over
               | DNS feels icky because the reason DNS traffic goes into a
               | separate accounting pool is so that the basic
               | infrastructure of the internet can be kept working
               | smoothly, so this is getting firmly into tragedy of the
               | commons territory.
        
             | hluska wrote:
             | This is theft. Stealing is illegal. Giving a blueprint for
             | how you stole is the icing on the prosecutorial cake
             | because you can't claim lack of knowledge if you create a
             | conspiracy to enable the theft.
             | 
             | This may be the dumbest write up I have ever read.
        
               | brailsafe wrote:
               | The nature of the non-transaction was such that they were
               | given access to a service that was constrained in certain
               | ways. They used the service, and the constraints that AC
               | technically applied still applied. They used what was
               | available to them under the constraints and weren't
               | required to pay for any other service but the removal of
               | the constraints. I don't see how any theft occurred.
               | 
               | Likewise illegality is just a boring and simple way to
               | dismiss someone on moral grounds, but laws are only as
               | effective as the level of agreement people have with
               | them. Drinking in the park is technically illegal, but I
               | don't care, the police don't care, nobody cares, unless
               | someone needs to care, and I'm going to do it anyway,
               | because the law does not make drinking in the park
               | inherently wrong, it just provides a framework for
               | telling you to stop if you're interfering with others in
               | a way that relates to alcohol consumption.
        
           | jxf wrote:
           | IMO a certain amount of youthful indiscretion that takes the
           | form of challenging systems and structures feels like it's
           | both tolerable and important. Agitation prevents
           | calcification.
        
           | ohyoutravel wrote:
           | I didn't see this, but the monster hacker blog post is up on
           | archive. Honestly the person sounds like a kid:
           | 
           | https://web.archive.org/web/20250823174801/https://bobdahack.
           | ..
        
           | pavel_lishin wrote:
           | I was about to correct you and say that bobdahacker hacked
           | McDonald's, but I guess he did both, and bragged about both.
        
           | anigbrowl wrote:
           | I wouldn't go as far as 'breaking the law', and I agree with
           | the author that the contractual terms ($31 for wifi) are a
           | shitty offer to a captive audience. But I'm also tired of
           | pseudolegalism being employed as figleaf for bragging about
           | the ability to bypass access controls and presumably making
           | everything run a bit slower for all the other passengers (the
           | author mentions that they gave up using it after a while
           | because the bandwidth was so limited).
           | 
           | Yes, long flights are miserable and air travel is a bit of a
           | ripoff. I choose to cope by treating it as an internet break
           | and enjoying a dense book.
        
         | CaptainOfCoit wrote:
         | Say you're on a plane from Canada to Hong Kong (random
         | example), which country's laws would be applicable here? The
         | country where the airplane is registered?
        
           | traceroute66 wrote:
           | > which country's laws would be applicable here? The country
           | where the airplane is registered?
           | 
           | For all intents and purposes it is the country of
           | registration of the aircraft.
           | 
           | There are one or two exceptions to the rule, but they would
           | not be applicable in this scenario. Mostly stuff relating to
           | air safety. For example, if the aircraft did something
           | against the aviaition laws of the country being overflown. Or
           | hijackings etc.
        
           | Traubenfuchs wrote:
           | Same country that would be responsible if you stab your seat
           | neighbor for taking too much space I'd guess.
        
             | traceroute66 wrote:
             | > if you stab your seat neighbor for taking too much space
             | 
             | IIRC the way it works is that when you land (destination or
             | forced landing elsewhere) the offender is delivered to the
             | local competent authorities.
             | 
             | They then undertake an initial investigation and decide
             | either to exercise their own jurisdiction or undertake
             | extradition proceedings to send the offender to the country
             | of registration of the aircraft.
             | 
             | In a scenario of (attempted)murder, I suspect that it is
             | highly likely it would be dealt with in the local courts
             | unless there was a specific external push for extradition.
             | 
             | The point of the convention is to ensure there is never no
             | jurisdiction, i.e. the country of registration to the
             | aircraft is always there as the ultimate fallback. The
             | wording doesn't seek to strictly define the jurisdiction,
             | which is why in most cases the delivery country has the
             | option to take jurisdiction.
        
           | jan_Sate wrote:
           | It depends on which jurisdiction region wants to enforce the
           | law. If someone wants to enforce a law, and it succeed, then
           | the law of that jurisdiction region applies.
        
       | andy99 wrote:
       | > The only downside was that although we broke through the
       | network restrictions and could access any website, the plane's
       | bandwidth was extremely limited, making web browsing quite
       | painful.
       | 
       | Unfortunately this is also the downside of paying. Many times I
       | have paid for internet, only to find it unusably bad. To be fair,
       | I just flew a transcontinental flight on Air Canada the other day
       | and the wifi was fine.
        
         | CrossVR wrote:
         | This is likely another layer of security that they didn't break
         | through:
         | 
         | To prevent chat apps from consuming lots of bandwidth typically
         | your connection is severely bandwidth restricted until you pay.
         | If they didn't then someone could simply stream movies from
         | their chat apps.
        
           | ms7m wrote:
           | I don't think so, compared to transcontinental, which lately
           | (before Starlink) has been using the cell towers on the
           | ground + satellite backhaul -- even paying would probably
           | still result in a garbage experience.
        
             | armada651 wrote:
             | The point is that if the connection does have more
             | bandwidth available they wouldn't get that extra bandwidth
             | without paying.
        
         | sheepscreek wrote:
         | I've been the unfortunate one who paid and endured the slow-
         | barely-usable/mostly unusable speeds. However, that was before
         | the Starlink era. So if you're gonna pay for WiFi, it's worth
         | checking if the flight is equipped with Starlink.
        
           | mjr00 wrote:
           | Yeah, I just flew WestJet from Canada to Honolulu and was
           | amazed; full 1080p YouTube with no hiccups and I was able to
           | play some (non-latency sensitive) online games, all over the
           | Pacific. This was fully intentional; there wasn't any back-
           | of-the-seat iPad for watching movies or anything, they
           | straight up tell you to use your own device and watch
           | Netflix. I did some research after and found a lot of
           | airlines in NA are going to be rolling out satellite internet
           | in the next year or two.
           | 
           | For some reason, being fully connected at 50mbps+ on a plane
           | seems more futuristic sci-fi to me than everything AI.
        
             | badc0ffee wrote:
             | > This was fully intentional; there wasn't any back-of-the-
             | seat iPad for watching movies or anything, they straight up
             | tell you to use your own device and watch Netflix.
             | 
             | Westjet has required you to use your own device for a long
             | time now (10 years?), but they offer an app/website and
             | streaming library that works for anyone who connects to the
             | in-plane wifi, unrelated to actual access to the internet.
             | 
             | Interesting that they're telling you to use your own
             | streaming app/account now. Did you still have to pay extra
             | for internet access? Was the Westjet streaming app still
             | available?
        
               | mjr00 wrote:
               | Nope, wifi was free. Well, have to sign up for WestJet
               | rewards, so the price is your personal data and such. No
               | WestJet streaming option, the information card in the
               | backseat tells you to use your own Netflix account; yes,
               | literally mentioning Netflix by name.
        
         | octo888 wrote:
         | Do consumer rights exist in the skies? Genuine question!
        
           | RandomBacon wrote:
           | Cruise ships wait until they get to international waters
           | before allowing gambling.
           | 
           | Maybe planes can offer gambling while over the ocean?
           | 
           | For the exec who pitches this at a board meeting: you're
           | welcome (cries)
        
       | ogurechny wrote:
       | Limiting availability of third party services based on local
       | service provider fee can only be done 100% reliably on a service
       | side through an agreement with that provider, i.e. WhatsApp needs
       | to disable certain functions to users coming from certain
       | dedicated links or IP ranges, or even based on live user status
       | metadata. There's an obvious size mismatch, and lack of incentive
       | to implement compartmentalisation only needed for some other
       | company. It also creates enormous shared responsibility and
       | potential circular finger pointing clown shows, all for
       | relatively tiny number of affected paying users.
       | 
       | Therefore, it is either done with least amount of work that is
       | "good enough", and can be done on a cheapest router (rate limit
       | to the absolute minimum, ban connections to ports 80 and 443,
       | maybe cut the traffic to most stable IP ranges of biggest
       | services, and regular person is going to state that "nothing else
       | works"), or trough very extensive commercial DPI with lots of
       | guessing and ad-hoc rules (if this feature is important for the
       | income, and many will try to game the system). So it's either
       | going to be as simple as in this example, or you'll compete with
       | the global army of detection rule authors.
       | 
       | Though I do like the wink-wink, nudge-nudge choice of proxy
       | software.
        
         | toast0 wrote:
         | FWIW, WhatsApp does (or did) support special price networking.
         | I used to be the engineering side of that. But the supported
         | offerrings were for special priced everything (text+mms+voip)
         | or just text+mms if real time voice and video was not to be
         | special priced. Text only was not a supported offering while I
         | was there. And you needed to be a mobile carrier to get the
         | information about IP ranges (the IP ranges were public but not
         | directly linked early on, but got limited later).
         | 
         | That said, _many_ networks did these sorts of things without
         | communicating with WhatsApp. Even without knowing IP ranges. WA
         | traffic is easy to spot. Chat has a destinctive protocol that
         | 's neither http, nor https; mms is https with obvious hostnames
         | in SNI; voip looks like voip.
         | 
         | You might be able to trick in-air wifi by looking like WA chat,
         | but I've never been interested enough to check while on a
         | plane. I'd rather use the time to watch awful movies on a tiny
         | screen with terrible audio conditions.
        
       | ajd555 wrote:
       | If a ping to a specific IP times out, I wouldn't say the IP is
       | blocked. It could be that ICMP specifically is blocked, following
       | some network rules on the firewall. This is pretty common in
       | entreprise networks to not allow endpoint discovery. I could be
       | missing something and happy to be corrected here, but I was
       | surprised to read that.
        
         | VladVladikoff wrote:
         | Yeah, ICMP tunnelling is also a common bypass method for
         | captive networks, so simply blocking all ICMP seems logical.
        
           | EvanAnderson wrote:
           | Every time I've had to fight with path MTU discovery not
           | working I've cursed the people who block all ICMP, though. If
           | ICMP echo / echo-reply is the problem just block that. At the
           | very least, allow destination unreachable / fragmentation
           | needed thru (type 3, code 4).
        
             | pixl97 wrote:
             | Most of the people blocking ICMP have no clue that ICMP
             | codes/types even exist.
        
             | yardstick wrote:
             | I am sure someone will find a way to exfiltrate data using
             | any ICMP type. How good are firewalls at validating the
             | packets are legit?
        
         | ogurechny wrote:
         | Yes, you need to test the exact protocol you want to use. This
         | means tcping/curl, TLS with proper certificates and SNI
         | domains, etc.
         | 
         | However, just as you make sure that the power supply actually
         | supplies power before dismantling something that refuses to
         | work down to the last washer, repairing network problems should
         | start with the basics. Simple test that does not work, or shows
         | something nonsensical, is a great hint that you forgot
         | something, or should start digging elsewhere.
        
         | EvanAnderson wrote:
         | I find it's important to remember, too, that a failed PING
         | tells you nothing other than your echo request did not receive
         | a response. If the remote host received your request, and if it
         | responded, are both things a failed PING can't tell you,
         | because both of those things could be true but you still end up
         | with a failed PING.
         | 
         | I've seen technicians get tripped up in troubleshooting
         | thinking that a failed PING tells them more than it does. When
         | the possibility of asymmetric return paths is involved it's
         | always important to remember how little a failed PING actually
         | tells you.
        
           | jacquesm wrote:
           | And that can be a lot more subtle than you might think. I've
           | had a persistent very hard to debug false alarm triggered on
           | pings _sometimes_ not making it and most of the time they
           | did. But very rarely that would happen three times in a row
           | and that was the threshold for raising an alarm. We spent
           | days on this. Finally, the root cause was tracked down to a
           | BNC  'T' connector at the back of a media adapter that
           | filtered out the header of some percentage of ICMP packets.
           | It is one of the weirdest IT problems I've ever encountered
           | and it makes me wonder how much of what we rely on is
           | actually marginal.
        
             | ceejayoz wrote:
             | > It is one of the weirdest IT problems I've ever
             | encountered and it makes me wonder how much of what we rely
             | on is actually marginal.
             | 
             | Vernor Vinge had a character who was a "Programmer-
             | Archeologist" on a relativistic starship. Feels more and
             | more prescient as time goes on.
        
               | pbh101 wrote:
               | I thought that too up until this GenAI moment, and now I
               | wonder if needing to be an archaeologist will be so
               | valuable if one can get your needs met by a quickly
               | GenAI-written script/program.
        
               | jacquesm wrote:
               | I've yet to have my needs met by a GenAI-written
               | script/program. Archaeologists tend to be a lot more
               | precise in their statements, especially about what is
               | speculation and what is not.
        
               | toast0 wrote:
               | I mean, if you're willing to accept AI slop, that's fine.
               | But if you're willing to accept AI slop, you'd probably
               | be willing to accept human slop (at least if it claims to
               | be AI) too, and then the job gets a lot easier.
        
               | palmotea wrote:
               | > I thought that too up until this GenAI moment, and now
               | I wonder if needing to be an archaeologist will be so
               | valuable if one can get your needs met by a quickly
               | GenAI-written script/program.
               | 
               | I never have actually read those books (though I read
               | some summaries about them, interesting concepts). My
               | understanding is the "programmer-archeologists" basically
               | had an archive of _massive quantities_ of _very high-
               | quality software_ that did pretty much anything you 'd
               | want software to do. So it made more sense to _find_ the
               | software you need and glue it together than write from
               | scratch.
               | 
               | And given GenAI doesn't write high quality software (at
               | least not yet, and hopefully never), I don't think that
               | "GenAI-written script/program" would be a good
               | replacement (though an AI archeologist might make more
               | sense, with such an archive).
        
               | cmehdy wrote:
               | I work at a company that invented an internal syntax to
               | compile into C++ code, that still relies on c-shell and
               | conventions taken when OS/2 was in use there, and with a
               | web of Jenkins instances and homemade wrappers and DBs to
               | build that stuff.
               | 
               | I can safely say that title exists already. And I value
               | my current experience as a humbling example of what is to
               | come as software becomes an older industry, and not just
               | a world of startups and their freshest
               | languages/frameworks/tools.
        
               | thwarted wrote:
               | The way you describe this system is exactly how I'd
               | describe a system I worked on in the early 90s at PW
               | (before it was PWC).
        
             | gosub100 wrote:
             | I'm a SRE and encountered this recently. To prevent DDoS,
             | there is a buffer setting on the kernel that will limit the
             | number of pings (a few settings actually). So if you have a
             | group of machines that all ping a single destination at
             | once, it's very possible to have some that fail to get a
             | reply.
        
               | jacquesm wrote:
               | Oh, that's nasty. How long did it take you to
               | troubleshoot that?
        
               | gosub100 wrote:
               | Relatively speaking, it wasn't that bad. It took a few
               | weeks of getting trouble tickets with no root cause, and
               | a bit of googling. But management wasn't okay with fixing
               | the root cause, instead they just increased the
               | timeout/retry window.
        
               | jacquesm wrote:
               | Wow. That's a classic. We were quite motivated because we
               | were the ones that got the automated alerts. I still see
               | them in my nightmares: "chopper is down". The machine was
               | called chopper, I'll never forget, it's been close to 30
               | years. My buddy Jasper and me spent multiple nights
               | trying to track it and when we finally found it we still
               | couldn't believe that that was it. But a simple swap was
               | proof.
        
               | dylan604 wrote:
               | Did someone yell for you to "Get to the choppa! Do it!
               | Now!!"?? Please say that's not been wasted!
        
               | gosub100 wrote:
               | whose chopper is this?
        
               | jacquesm wrote:
               | I think we were past the point of humor during that
               | particular episode but there was a reason it was named
               | like it was.
        
               | dylan604 wrote:
               | if it wasn't an Arnie reference, could it have been a
               | Stand By Me reference, "Chopper, sick balls"? or Eric
               | Bana's Chopper: "if you keep stabbing me, I'm gonna die"?
               | 
               | clearly, i'm the type where everything is a movie
               | reference, or it's a missed opportunity
        
               | pixl97 wrote:
               | It's for reasons like this that ping is one of the worst
               | protocols to use for aliveness.
               | 
               | Even worse is I've had completely dead Linux boxes that
               | will gladly respond to ping and nothing else.
        
           | webstrand wrote:
           | I had an experience recently setting up a third-party VPN
           | where the echo responses were being delivered to the correct
           | (host,interface) but with the wrong destination address (not
           | the same as made the request)
        
           | kulahan wrote:
           | I've always assumed that in situations like this, a
           | traceroute is better. You can get more information simply by
           | reaching the next stage in the trace, even if you're given
           | zero information beyond "I'm now at the next server".
        
         | throwaway173738 wrote:
         | I've had to explain this over and over throughout my career.
         | The only way to know if something is accessible is to try the
         | exact endpoint and protocol. Even application-aware firewalls
         | will mess with things at times.
        
         | _trampeltier wrote:
         | In my old company it was the oposite. Ping worked allways, even
         | when you where blocked on to a specific VLAN.
        
           | EvanAnderson wrote:
           | I've worked in gigs that wanted that. They were all about
           | segmentation, but wanted ICMP echo / response available
           | throughout.
           | 
           | Edit: I wonder if any "enterprise" firewalls do ICMP echo
           | proxying. Having the firewall replace the payload would
           | remove some of the tunneling capability (thought I assume you
           | could still finagle a side channel by just timing the
           | packets) but would also eliminate some of the utility (since
           | being able to craft the payload provides a way to test for
           | specific bit patterns in packets causing problems).
        
             | yardstick wrote:
             | It's been years but I've likely used NAT to redirect ICMP
             | pings so the local firewall responds rather than whatever
             | boat they were trying to reach.
             | 
             | Systems change - a server that once used to respond to
             | pings may no longer do so, but client software may not be
             | updated to stop doing pings before connecting to the actual
             | service on the server. In an ideal world the client code
             | would be updated, in practice: hello firewall.
        
       | dogtorwoof wrote:
       | AC offers free WhatsApp, iMessage, messenger in most flights. You
       | can ask meta through WhatsApp to effectively browse the net :)
        
         | CaptainOfCoit wrote:
         | Ah "network neutrality", how you won initially yet lost over
         | time...
        
           | cced wrote:
           | I mean, if everyone was watching 4k YouTube videos they
           | probably couldn't support it, right?
        
           | axus wrote:
           | Now imagine the same restrictions on your home Internet
        
           | jeroenhd wrote:
           | I don't think there are any net neutrality laws that don't
           | exempt things like in-flight Wi-Fi, where the upstream is so
           | heavily restricted that providing balanced services to
           | everyone is basically impossible or leaves the entire
           | connection useless.
           | 
           | With Starlink things may be looking a bit better, but I think
           | demanding net neutrality on in-flight satellite internet and
           | plane-to-cell-tower internet is excessive.
        
             | Dylan16807 wrote:
             | You can still have a very slow free tier, a normal tier,
             | and a quality video tier. Limited bandwidth is not a good
             | reason to abandon net neutrality.
        
         | ogurechny wrote:
         | Many years ago, some dial-up providers in my city offered free
         | public logins to use their websites (for scratch card
         | activation, account renewal, user guides, and so on). Some
         | companies also paid ISPs to have their sites and services
         | accessible in similar fashion for promotional reasons.
         | 
         | At a certain provider, all those free logins used the same
         | firewall configuration to only allow traffic to those free
         | services and ISP site, probably for simplicity, so all of them
         | were accessible with any promotional login. Most of them were
         | not useful (to me), but different agreements with ISP resulted
         | in different call time limit until hang-up, 10-15 minutes
         | instead of 3-5.
         | 
         | However, the main treasure was the addition of external page
         | translation service as a feature on some big site. Back then,
         | it was strictly static and server-side, URL in request gave you
         | its HTML source with translated text strings and absolute paths
         | to external resources, so in order for translation to work,
         | users needed to be able to access that third party server, too.
         | Obviously, if you gave it any other URL, the server would also
         | grab it to translate (and choosing least similar language in
         | parameters would leave most of the page text intact).
         | 
         | You can imagine that having a browser supporting tabs and
         | switching media off was very handy for loading as many free web
         | pages in text only form as those dial-up sessions allowed.
         | 
         | Obviously, WWW-to-email services for people who only paid for
         | mail server access had existed even before that.
        
       | eps wrote:
       | "All new is something already known, but well forgotten."
       | 
       | Escaping locked down networks by tunneling things over DNS is one
       | of these things. We've used it back in 00's to get out of
       | restrictive hotel networks. Not even WiFi, but the actual wired
       | Ethernet ones.
        
       | bawolff wrote:
       | I feel like you have to be brave messing with a plane's network.
       | People tend to get really touchy when airplanes are involved.
        
         | CaptainOfCoit wrote:
         | Imagine if anything essential/of value/useful was exposed on
         | the passengers WiFi, this story could have been a huge scoop.
         | But alas, everything is heavily separated.
        
         | reactordev wrote:
         | I was going to say this too.
         | 
         | I once merely mentioned the words "Heart Attack" on a plane and
         | was kicked off by the flight attendants. No context, they just
         | heard the words and forced me off.
         | 
         | There are things that trigger them because of laws and
         | regulations like mentioning "bomb" (even if you're describing
         | something fantastic).
         | 
         | So messing with the gogo flight entertainment is up there with
         | flirting with terrorism charges.
        
           | yabones wrote:
           | I'm pretty "curious" when it comes to public networks. I'll
           | scan coffee shops, stadiums, hotels, bus hotspots, anything I
           | can connect to. Some networks are set up well, others not so
           | much.
           | 
           | I would never in a thousand years run a sweep on an airplane
           | network. That's massively risky, to the point you might never
           | be allowed on a jet again. Anything to do with aviation I am
           | on my absolute best behaviour.
        
             | zavec wrote:
             | Without commenting on the appropriateness of what they did,
             | the author doesn't say they did anything like a sweep. It
             | looks like they were manually poking a few things with dig
             | and ping, not firing up nmap.
        
               | reactordev wrote:
               | Circumventing security on a network, on a plane, is
               | definitely up there regardless if you sweeped or not.
               | IANAL but that could put you in DHS crosshairs.
        
               | ogurechny wrote:
               | The exaltation displayed in this discussion thread is
               | something everyone should ponder about. Some stupidity
               | specific to certain era and place on Earth, just another
               | tumour of uncontrolled bureaucracy which always grows, is
               | discussed as some eternal property of God-given Universe.
               | 
               | Hijacked plane is a popular media spectacle with lots of
               | ties to other images and scenes. Millions are ready to
               | discuss it, or listen to the thrilling stories. "This is
               | important for security!" is a shazam in that context. At
               | the same time, much closer and routine dangers directly
               | affecting many people (power plants, refineries,
               | railroads and so on) are kept in check by underpaid
               | workers who can't even make companies fix sensors or
               | replace something until it is rusted through.
               | Effectively, "this is not important for anything", nor
               | public is interested in TV shows about working pipeline
               | that is not getting blown up. Those who want money and
               | power naturally stick to impressions that work for the
               | crowd they are given.
               | 
               | Propaganda is most successful when people do the required
               | thing on their own, agree that it's absolutely impossible
               | to evade, and even encourage each other. Something in
               | this day and age makes people themselves adore certain
               | forms of propaganda, and even demand to be told specific
               | lies. Among other things, images of stupid social
               | machines crushing someone ("they'll put you on the list",
               | etc.) seem to weirdly stimulate the crowd.
               | 
               | Even in so-called globalised world there are examples
               | that crack the habituation. In country A, any big
               | gathering of people needs to be formally approved,
               | supplied with hordes of policemen (thankfully, not
               | tanks), fences (thankfully, not barbed wire), entrance
               | searches (thankfully, without stripping). When you ask
               | anyone about that, they promptly respond with "What if
               | terrorists/enemies decide to attack the crowd?" or "What
               | if they start to riot?" (notice that "they"), etc. Even
               | most obvious security theatre acts are automatically
               | accepted with promotion to "psychological stuff that
               | helps to detect _those people_ in the crowd". In country
               | B, no less "civilised", the same event is handled by some
               | private company that is mostly worried about portable
               | toilets or electric generators, and people come freely to
               | the venue if they like it (just buy the ticket).
               | 
               | The odds of something wrong happening are roughly the
               | same, but people reason about themselves and those around
               | them very differently. That mental picture of the world
               | shapes the thing that happens, not the alleged expert
               | opinions or calculations.
        
               | woodrowbarlow wrote:
               | i appreciated this comment, even though it downplays real
               | pragmatic concerns. from a security perspective, should
               | getting on an airplane (especially for domestic flights)
               | really be all that different from getting on a bus? are
               | the potential outcomes different enough to justify the
               | differences in security measures?
        
             | ActorNightly wrote:
             | The router is 100% separated from the rest of the plane,
             | and has a fuse on the power. You can't really mess anything
             | up and the only chance of you getting caught is if you
             | somehow manage to ddos the network.
             | 
             | The fun thing to do on the plane is clone the wifi and add
             | an option to log in with google or meta or apple
             | credentials....
        
           | throw83949r049 wrote:
           | I do not buy this.
           | 
           | I was on airplane with large aggressive dog, that was
           | harassing other passengers. I was worried it would ampute my
           | limb mid flight.
           | 
           | I voluntary left before take off, dog stayed!
        
             | FlynnLivesMattr wrote:
             | I agree, this sounds a bit too stretched. Or maybe they
             | were looking for any excuse under the sun to get someone
             | off what could have been an overbooked flight. But just
             | saying the two words "heart attack" would not be enough
        
           | Mattwmaster58 wrote:
           | > I once merely mentioned the words "Heart Attack" on a plane
           | and was kicked off by the flight attendants.
           | 
           | Well now you have a chance to tell your side - were you
           | merely sitting and just uttered the words "heart attack" for
           | no externally apparent reason?
        
         | FlynnLivesMattr wrote:
         | If you move to an empty seat to prevent WiFi signal strength
         | triangulation, and assuming the cabin has no cameras, you
         | didn't auth to the network with identifiable information,
         | actually encrypt your Xray proxy connection (which OP didn't),
         | and you have MAC randomization on, there's next to no way the
         | airliner would be able (or even care) to identify that you did
         | what was described in the article. Sure, they could use DPI and
         | behavioral analysis to _detect_ you were misusing the network,
         | but if they 're doing that, they would just block this sort of
         | "backdoor" from the get-go.
         | 
         | I'll echo the article's disclaimer: This reply is intended
         | solely for educational and research purposes. I affirm the
         | strict adherence to all relevant regulations and service terms.
        
           | ryandrake wrote:
           | I highly doubt any airline staff are on your flight (or even
           | remotely) counter-hacking one in a billion passengers messing
           | around with the in-flight WiFi. That $30.75 they're not
           | getting doesn't justify anyone looking into it.
        
             | wildzzz wrote:
             | Plus, the free tier is usually set to a very low QoS such
             | that chat is pretty much the only thing you'd bother doing.
             | Short videos will download in a reasonable amount of time
             | but on average, the actual data rate is small. There's only
             | so much bandwidth available and they want to make the $30
             | somewhat of a value for those needing full Internet access.
             | One person absolutely saturating the limited bandwidth
             | allowed for the free tier is not going to make much of a
             | difference for everyone else but it could be an issue if
             | everyone was doing it (like if a VPN was all that was
             | required to bypass the restrictions).
        
         | bennydog224 wrote:
         | Brave or stupid.
        
         | jeroenhd wrote:
         | I refuse to believe that anything important for flying the
         | plane is actually hooked up to the system providing Netflix to
         | passengers.
         | 
         | People do get nervous, and in theory you could probably break
         | some kind of informational system utility if you kernel panic
         | the box that booms up to the satellite receiver, but unless
         | you're trying to get root on the plane's routers I don't
         | believe there's a need to feel brave.
         | 
         | The braver part is publishing the results of this stuff online
         | under your own name.
        
           | notahacker wrote:
           | yeah, you're not interfering with anything flying the plane
           | through the IFE system, and it won't be the same bandwidth
           | they use for comms either (there might be some semi-sensitive
           | passenger information stored on the in-flight server, but
           | entirely different techniques would be needed to bypass
           | whatever security that's wrapped in).
           | 
           | But "hacking" on an aircraft isn't going to be looked on
           | particularly sympathetically by courts
        
           | chrisbrandow wrote:
           | I wouldn't expect that either given the little that I know
           | about the rigorous software requirements for aviation.
           | 
           | But I assume that neither of us has anywhere near enough
           | expertise to "refuse" to believe that any computer/software
           | system could be used in dangerously absurd ways even
           | accidentally.
        
       | ajross wrote:
       | tl;dr: The firewall on the plane allows any traffic to pass on
       | port 53 (to allow for DNS queries) but doesn't do any state
       | inspection or rate limiting so you can do whatever you want on
       | it.
       | 
       | > My roommate spent about an hour setting up a proxy server
       | exposing port 53 using xray 1, and sent me the configuration via
       | WeChat:
       | 
       | An hour!? As opposed to just spinning up an sshd on that port and
       | coming in using ssh -D to establish a local socks proxy?
        
       | crispair wrote:
       | This was a thing back in the days too. You'd use a tool like
       | iodine to tunnel ip through dns queries. Fun!
        
       | MarsIronPI wrote:
       | My question is: would proxying over SSH running on port 53 have
       | worked? Seems simpler than using Xray.
        
         | Doohickey-d wrote:
         | On some networks, yes: I used to use a prepay mobile network (=
         | buy a fixed quantity of GBs in advance, use them, once you run
         | out, you get a restricted captive portal where you can buy
         | more, just like on this flight). But all traffic on port 53 was
         | allowed, it didn't need to be actual DNS traffic.
         | 
         | There's even some commercial VPN providers which offer openVPN
         | on port 53.
        
         | noxvilleza wrote:
         | If they had a ssh server on the remote machine they could have
         | also done something like `ssh -g -ND 53 root@localhost` from
         | the remote machine, which would have exposed a remote-
         | accessible SOCKS proxy on port 53.
        
       | appreciatorBus wrote:
       | > Here we exploited a simple cognitive bias: not all services
       | using port 53 are DNS query requests.
       | 
       | Eh, I don't think this is a result of cognitive bias. I'm sure
       | the people involved in creating whatever hardware or software is
       | running the network know that you can run other stuff on ports.
       | More likely the extra effort involved in inspecting packets was
       | not deemed worth the risk, a decision either made by the
       | manufacturer of the hardware/software, or someone on Air Canada's
       | IT team.
        
         | gwbas1c wrote:
         | To quote https://news.ycombinator.com/item?id=45537828
         | 
         | > This is likely another layer of security that they didn't
         | break through:
         | 
         | > To prevent chat apps from consuming lots of bandwidth
         | typically your connection is severely bandwidth restricted
         | until you pay. If they didn't then someone could simply stream
         | movies from their chat apps.
        
       | stackedinserter wrote:
       | Why does Air Canada charges $30 for internet, that's brutal.
       | Especially on 12hr flight where it should be provided for free
       | imo.
        
         | huhtenberg wrote:
         | That's Air Canada. They are already making you a favor by
         | allowing on board.
        
         | gruez wrote:
         | >Especially on 12hr flight where it should be provided for free
         | imo.
         | 
         | "Should" in the sense that "everyone _should_ get free food,
         | housing, and healthcare " or that other airlines actually
         | provide it for free? I don't know of any airline that provides
         | it for free, the most is some Asian/Gulf airlines providing
         | "free for 1 hour" or similar. Compared to that, "free texting,
         | unlimited" doesn't seem too bad, considering there are also
         | trans-continental flights with no internet access at all.
        
           | apple1417 wrote:
           | On a recent 12h Air New Zealand flight I went on they offered
           | free wifi for everyone. They say you can:
           | 
           | - Browse the web.
           | 
           | - Send and receive emails and messages.
           | 
           | - Check and post to social media
           | 
           | In practice I think they just whitelist a few messenger apps.
           | Everything else was unusable - I couldn't even load this
           | site. Only had my phone so couldn't check if I was actually
           | receiving any bytes from other sites, but it at least wasn't
           | immediately blocked.
        
             | theideaofcoffee wrote:
             | > - Browse the web.
             | 
             | > - Check and post to social media
             | 
             | > In practice I think they just whitelist a few messenger
             | apps. Everything else was unusable
             | 
             | That was probably intentional, because to the vast majority
             | of the users of these services, 'the web' is just a handful
             | of the same social sites. As long as they can post a few
             | things about their trip, that's the extent of the web
             | access that they need or care to want. Sucks when you're
             | expecting the whole kit and kaboodle, but the airlines seem
             | to know their customers.
        
           | stackedinserter wrote:
           | "Should" in the sense that they need to provide basic dignity
           | to people on board. Same as toilet and basic necessities like
           | glass of water or very basic meal.
           | 
           | Although "dignity" and modern planes can't be used in the
           | same sentence, unless you pay 5x for business class,
           | passengers are humiliated less there at least.
        
         | triceratops wrote:
         | > Especially on 12hr flight where it should be provided for
         | free imo
         | 
         | That's junkie talk /s
         | 
         | No but seriously if you think Internet access is so vital that
         | it has to be provided for free on a long-ish flight, you may
         | have a problem. Watch an in-flight movie, read a book, take a
         | nap, look out the window. There are many ways to pass 12 hours.
        
           | stackedinserter wrote:
           | > look out the window
           | 
           | They took even this basic pleasure. On B787 flights crew
           | forcibly dim windows for the whole flight. I guess it will be
           | paid feature soon.
        
         | adolph wrote:
         | If you had a window seat you could make bank with a starlink
         | mini and undercut the Air Canada by a small amount, like $40
         | Canadian. Just use pfSense Captive Portal and make sure you
         | forward any port 53 or 853 to the external interface to the
         | local DNS.
        
       | Nzen wrote:
       | Could y'all point at instructions for how to imitate this limited
       | internet situation ?
       | 
       | I ask because, two years ago, I was able to circumvent the
       | Windows-11-requires-internet-and-a-microsoft-account part of the
       | set up for a new laptop computer by doing this on a flight.
       | Apparently, connecting to the airplane wifi (without yet logging
       | in) was enough to satisfy the OS set-up, but limited enough that
       | my laptop didn't require a microsoft account. With windows 10 now
       | end of life, I will probably get a new desktop computer and would
       | like to repeat the feat at home. Thanks
        
         | gruez wrote:
         | >Apparently, connecting to the airplane wifi (without yet
         | logging in) was enough to satisfy the OS set-up, but limited
         | enough that it didn't require a microsoft account.
         | 
         | Set up a wifi network with no internet? If you have a separate
         | router/modem, just unplug your modem from your router. If your
         | mode/router is combined unplug the coax/fiber/phone line.
        
         | jeroenhd wrote:
         | Boot up a router without any ethernet cables hooked up to it.
         | Or turn on tethering on your phone but disable mobile data.
         | 
         | I believe this trick doesn't work on Windows 11 anymore,
         | though. Microsoft will happily wait for you to move some place
         | with internet access to finish the OOBE, especially with
         | upcoming changes where they disable various internal mechanisms
         | to bypass the account restrictions.
         | 
         | For about 30 bucks (or a crack) you get more life out of
         | Windows 10 if switching to Linux isn't an option for you.
         | You'll need to log in to an MS account once every three months
         | to keep that going, but you can log out in between. If you live
         | in the EU, you'll get the first year for free if you just sign
         | in to an MS account, which I believe will also work as long as
         | you sign in once every three months to keep the computer
         | registered for updates.
        
       | rubatuga wrote:
       | I never understood the need to post about this. Just pay the $30
       | or just keep quiet so others can continue to browse for free.
        
       | dlenski wrote:
       | Great writeup.
       | 
       | I have done similar things on several long flights.
       | 
       | Very often, there is at least one large cloud provider or CDN
       | (e.g. Microsoft/Azure or Amazon/AWS or Google/GCP) that is
       | whitelisted by the in-flight Internet gateway so that it can
       | serve static pages, and I can get access to all the sites hosted
       | by that provider simply by using domain fronting (which the
       | author of this post describes as "disguise domain":
       | https://ramsayleung.github.io/en/post/2025/a_story_about_byp...)
        
       | pehtis wrote:
       | Another option would be to setup a wireguard server listening on
       | 53. Wireguard traffic is UDP so it would work even if TCP DNS
       | requests are blocked. And it would also make the client
       | configuration much easier, ie just connect to the wireguard
       | server.
        
       | NoahZuniga wrote:
       | I'm not following the reasoning here:
       | 
       | > Since acwifi.com is accessible but github.com is not, is it
       | possible that the network has imposed restrictions on the DNS
       | server, only resolving domain names within a whitelist (such as
       | instant messaging domains)?
       | 
       | > If this is the case, can I modify /etc/hosts to disguise my
       | server as acwifi.com, so that all request traffic passes through
       | my server before reaching the target website (github.com)?
       | 
       | But by putting the host in /etc/hosts, you're skipping asking the
       | planes DNS server, so how are you "disguising" an external
       | server? And why go through the effort of proxying through
       | acwifi.com instead of going straight to the example of github.com
        
         | avidiax wrote:
         | It could be that they allow any HTTP/HTTPS request that has
         | Host: acwifi.com
         | 
         | regardless of whether the IP address destination of the request
         | is valid for acwifi.com.
         | 
         | You see these sorts of shenanigans being used to get around
         | country-wide firewalls. Plenty of deep packet inspection is
         | unable to handle edge cases like the "Host:" header being
         | misleading, having it fragmented into two TCP packets, etc. See
         | "domain fronting".
        
       | otterley wrote:
       | Lesson for implementers: block all DNS requests from customers
       | unless they are addressed to a onboard DNS cache (whose IP
       | address is supplied by the DHCP response).
        
       | pumanoir wrote:
       | Where can i learn to do this kind of things? Any book(s) that'd
       | teach this kind of stuff?
        
         | mcpherrinm wrote:
         | I don't know specifically what skills you're interested in, but
         | this is all pretty much networking fundamentals.
         | 
         | I think I learned most of what I'd need to do this in 'TCP/IP
         | Illustrated: Volume 1'.
         | 
         | There's plenty of "network penetration testing" type books
         | which might also be of interest, though I don't have a specific
         | recommendation here.
         | 
         | There's a wider set of books at
         | https://github.com/jacobian/infosec-engineering that's pretty
         | good too, though it's a wider set of things than this.
        
           | pumanoir wrote:
           | Excellent, thanks! Just took a look at "TCP/IP Illustrated:
           | Volume 1" and was exactly what I was looking for. Any book
           | along those lines that is compressed/water down (just to get
           | started over a weekend)?
        
       | Evidlo wrote:
       | Why is there an in-flight internet bypass blog post every year,
       | but they never mention Iodine?
        
       | t1234s wrote:
       | Planes that use the Panasonic system allow access to the full
       | *.paypal.com domain to allow the paywall to work. If there is a
       | way to somehow proxy all your traffic though something under
       | paypal.com you could get free wifi on certain flight. Or you can
       | pass the time away reading all the paypal API documentation.
        
       | joshheyse wrote:
       | I'm guessing the speeds were slow because QOS was limiting the
       | slowed for what was speed to be a chat only connection.
       | 
       | What not just spoof the MAC address of "machine" that has paid.
       | 
       | I had written a utility that monitors MAC address on the network
       | and tries them each until it finds on that is allowed.
       | 
       | Looks like someone released an app to do just that.
       | 
       | https://github.com/t-mullen/wififox
        
       | barbs wrote:
       | Can someone please explain what project X/Xray is? Judging from
       | the context I imagine it's some sort of proxying software but I
       | can't seem to find out more. The website and github seem to be
       | littered with vague jargon or is in Chinese and Googling brings
       | up something called XTLS?
        
       ___________________________________________________________________
       (page generated 2025-10-10 23:00 UTC)