[HN Gopher] TikTok requests access to devices on local network
       ___________________________________________________________________
        
       TikTok requests access to devices on local network
        
       Author : hacky_engineer
       Score  : 255 points
       Date   : 2021-08-16 16:02 UTC (6 hours ago)
        
 (HTM) web link (twitter.com)
 (TXT) w3m dump (twitter.com)
        
       | hokkos wrote:
       | I'm pretty sure they use it for targeting, I remember tiktok
       | presenting me video of interest shared by other under the same
       | wifi.
        
         | SubiculumCode wrote:
         | Very curios coincidence. I watched a little TikTok this morning
         | and found my daughter's account in my feed.
        
       | TchoBeer wrote:
       | This shouldn't be news, tons of apps do this; I suspect it's for
       | something like Chromecasting, maybe it collects telemetry too?,
       | either way not at all specific to TikTok.
        
       | wyldfire wrote:
       | Many apps need to peer with a very short list of remote nodes.
       | There are only some rare apps that need blanket network access to
       | any other node. Maybe it's time for more permissions constraints
       | to be applied?
        
       | q-rews wrote:
       | Is it TikTok or is it just because of a captive portal on the
       | WiFi?
       | 
       | It happened to me just yesterday: "Why does X require local
       | network access? Ugh." A minute later "Oh, Y is also requiring
       | network access."
       | 
       | Yes, I was on a public wifi.
       | 
       | This may be 100% Apple's fault, everyone here is just commenting
       | on a photo and not confirming that they also saw the message
       | today.
        
         | Too wrote:
         | I had same thing happen some days ago while rebooting my modem
         | at home after accidentally unplugging it.
         | 
         | All kinds of apps I use regularly, which have absolutely no use
         | for it, started asking for permission to list devices on local
         | network.
        
       | antioxidant wrote:
       | They used to check your clipboard the whole time too.
       | 
       | They use the local network as one of their sensors to identify
       | you (fingerprinting). However they have plenty more (see their
       | privacy policy).
        
         | dwild wrote:
         | > They use the local network as one of their sensors to
         | identify you (fingerprinting).
         | 
         | But why? It's an app... I guess this can allow them to link
         | other people in your household to you, but isn't the wifi
         | network name already available?
        
         | rvz wrote:
         | > They use the local network as one of their sensors to
         | identify you (fingerprinting).
         | 
         | Well they already disclosed the other ways they are identifying
         | you in [0] but have they disclosed this one that finds other
         | devices on your local network for 'fingerprinting' purposes in
         | their privacy policy?
         | 
         | The worst thing about this is that they haven't disclosed as to
         | why they are specifically doing this. Not even the commenters
         | here know why, since we can rule out AirPlay and Chromecast
         | support as valid reasons to request such permissions.
         | 
         | [0] https://www.tiktok.com/legal/privacy-policy?lang=en
        
         | phkahler wrote:
         | >> They used to check your clipboard the whole time too.
         | 
         | That's a design error on the UI side. An app should not have
         | read access to the clipboard, it should have the ability to
         | accept data from the clipboard when the user pastes it.
        
           | f1refly wrote:
           | There's legitamate uses though, of which I was made painfully
           | aware when google crippled the api and kde connect clipboard
           | sync became way less impressive
        
           | Spivak wrote:
           | The problem is with clipboard access is because apps abuse it
           | not because it's a problem that have read access at all.
           | Google Maps pulling my clipboard which has an address in it
           | as the top suggestion for destinations is a good thing and
           | respect the user's time.
        
         | _trampeltier wrote:
         | Is there a way to check if a website does read your clipboard.
         | I know you have to interact with the site, so they can read it.
         | So in theorie, a website can read your clipboard every time you
         | click on something, is this true?
        
           | detaro wrote:
           | AFAIK it's not, reading the clipboard requires an explicit
           | "paste" command triggered by the user or an explicitly
           | granted permission.
        
         | judge2020 wrote:
         | > They used to check your clipboard the whole time too.
         | 
         | To be fair quite a lot of apps did this to enable deep
         | links/automatically opening certain clipboard links. Every big
         | app has changed this to no longer show the 'pasted from'
         | notification. And it was never shown that they export those
         | clipboard contents to homebase.
        
           | colechristensen wrote:
           | >it was never shown that they export those clipboard contents
           | to homebase
           | 
           | When it comes to an app gathering data for a company, is
           | anybody really willing to give the app makers the benefit of
           | the doubt? If there is information available, somebody is
           | going to take it and try to squeeze a penny out of it. Not
           | everybody, but when it gives you a competitive advantage it
           | has a tendency to grow.
        
             | judge2020 wrote:
             | The cool thing about phones is that you can MITM yourself
             | and see what apps are sending, assuming they don't
             | certificate pin (which TikTok doesn't). The person that
             | reported this during the beta period didn't find any
             | evidence when doing so.
             | 
             | https://old.reddit.com/r/videos/comments/fxgi06/not_new_new
             | s...
        
               | duiker101 wrote:
               | Can you actually still widely do this? Last time I
               | checked on the latest versions of Android apps don't
               | accept user certificates so you can't really do much
               | about any https traffic, which really is the bulk.
        
               | k1rcher wrote:
               | From a legitimate reverse engineering/security auditing
               | standpoint, cert pinning is generally very trivial to
               | bypass.
               | 
               | see: Frida, xposed framework (not sure if still relevant)
        
               | judge2020 wrote:
               | The basis of many enterprise networks is device-installed
               | CAs so I would be thoroughly surprised. iOS at least
               | still allows you to install a custom CA and only a few
               | apps will refuse to work with it, who likely reject
               | connections that aren't secured via a specific CA.
        
               | jeroenhd wrote:
               | You can, on a rooted phone. There's ways to install a CA
               | certificate with root (described in my only popular blog
               | post) but there's also alternatives, like using Frida to
               | disable TLS verification all together.
               | 
               | It's certainly not as easy and reliable as it used to be,
               | but it's still common for security research to use these
               | tactics to see what apps are doing.
        
           | MichaelGroves wrote:
           | "Lots of people do it" should never be considered a
           | legitimate excuse. Trying to use that excuse should get you
           | kicked out of the meeting room.
        
             | dudus wrote:
             | Everything TikTok is usually linked to malice and espionage
             | from China. If this is a common industry practice at the
             | very least you give it the benefit of the doubt. It doesn't
             | make it ok. It just makes it not automatically linked to
             | international cyber warfare.
        
               | smolder wrote:
               | The incidents that might qualify as cyber warfare could
               | also just be looked at as the same struggle for power on
               | a different front, compared to economics. It can't be
               | lost on Chinese leaders how valuable it is to the US to
               | have so much money and data flowing through its domestic
               | tech companies. Tech companies can't cross the line into
               | cyber warfare themselves and get a pass on it, but they
               | do play a role in it.
        
             | vlunkr wrote:
             | I don't think they're trying to say it's a valid excuse,
             | just that there are reasons to check clipboard content that
             | aren't malicious.
        
             | hungryhobo wrote:
             | why should it get you kicked out of the meeting room? if
             | everyone else is doing it and have a better ux, i'd imagine
             | you'd be kicked out of the meeting roomm if you're not
             | doing it.
        
             | blackoil wrote:
             | Theoretically maybe, practically we have a proverbs 'No one
             | is fired for buying (IBM|MS|Google|AWS)'
        
           | pizza wrote:
           | > Every big app has changed this to no longer show the
           | 'pasted from' notification.
           | 
           | Is that because they stopped checking your clipboard, or
           | because they managed to check in a way that doesn't alert the
           | user?
        
             | _fzslm wrote:
             | afaik apps can detect patterns on the pasteboard without
             | triggering the notification (i.e. check if the URL is a
             | TikTok URL or not), but they can't actually access the
             | contents without triggering the notification. it's enforced
             | by the pasteboard API on iOS.
             | 
             | so they probably updated their apps to perform this check
             | before doing anything.
        
           | zuhsetaqi wrote:
           | "Okay so TikTok is grabbing the contents of my clipboard
           | every 1-3 keystrokes. iOS 14 is snitching on it with the new
           | paste notification pic.twitter.com/OSXP43t5SZ "
           | 
           | -- Jeremy Burge (@jeremyburge) June 24, 2020
           | 
           | TikTok wasn't checking it for link opening ...
        
       | diebeforei485 wrote:
       | Some other apps (Signal?) have also done this out of the blue,
       | though they may have since added a UI around this.
       | 
       | Regardless, Apple has done the right thing by putting this behind
       | a permissions box, but the developer should be required to have
       | some sort of explanation string of why they need this.
        
         | phreack wrote:
         | Apple does require a string for location access motivation,
         | hopefully they'll do that for this one as well. Ideally all of
         | them.
        
         | alerighi wrote:
         | That thing makes it annoying for the kind of applications my
         | company does, that needs to communicate with other devices on
         | the local network.
         | 
         | It's annoying because it's not like other permissions, where
         | you can ask the OS to prompt the user, and check if the user
         | granted it or not, but it's some special permission. If the
         | user, by mistake because it doesn't know that it's needed,
         | doesn't give it one time it's impossible to ask again, and the
         | app doesn't have a way to know that the permission is not
         | granted. It's just things that the customer service has to
         | handle, and that is bad.
         | 
         | Sure, right to ask a permission, so make it like a regular
         | permission as the location permission.
        
           | t0ps0il wrote:
           | > It's annoying because it's not like other permissions
           | 
           | Normally if I want to use a permission, say location, I need
           | to provide a value for given permission in my app's
           | `info.plist` file, and if I don't and the app tries to grab
           | the current location, it crashes with logs yelling at me to
           | provide a description for the location privacy key.
           | 
           | With local network permissions it's different.
           | 
           | I've never had to do any local networking in my career as an
           | iOS dev so downloaded Apple's peer to peer example app (https
           | ://developer.apple.com/documentation/network/building_a...)
           | and removed the `Privacy - Local Network Usage Description`
           | key/value pair from the `info.plist` file and ran the app on
           | my device.
           | 
           | I fully expected a crash with a description telling me to add
           | this key but iOS just filled in the missing description with
           | a default value and asked away. I wonder why that permission
           | is treated differently from the rest?
        
           | swiley wrote:
           | If you're truly not being malicious then open source your app
           | and get it added to the alpine repos so people can run it in
           | ish.
        
         | adrr wrote:
         | I assume signal is udp hole punching to get around NAT.
        
           | ergl wrote:
           | Signal uses local networking for the account migration
           | functionality: https://support.signal.org/hc/en-
           | us/articles/360007059752-Ba...
           | 
           | You scan a QR code with one device and it transfers the
           | entire account state to the new phone.
        
           | danlugo92 wrote:
           | What's some good resources on understanding NAT and udp hole
           | punching that explain it in an intuitive manner?
        
             | zamadatix wrote:
             | The simplest take on the concept is get a 3rd party with a
             | public address to exchange the current port tuples used to
             | connect to it between the 2 clients so the clients can then
             | use this information to connect directly.
             | 
             | Beyond the basic take on it there really isn't an intuitive
             | single explanation because "simple" things like "NAT
             | traversal" quickly turn into "Full-cone NAT to Port-
             | restricted NAT with UPnP behind CG-NAT" individual corner
             | cases endlessly fighting the need to just go to IPv6.
        
       | uniqueuid wrote:
       | Just to add: Scanning networks to gather data seems pretty
       | popular these days - smart tvs have done so, and even the ebay
       | site used to portscan visitors [1].
       | 
       | [edit] And of course, there's WebRTC leaking your local IP -
       | which ublock origin can specifically block [2].
       | 
       | [1] https://www.bleepingcomputer.com/news/security/ebay-port-
       | sca...
       | 
       | [2] https://github.com/gorhill/uBlock/wiki/Prevent-WebRTC-
       | from-l...
        
         | nostrademons wrote:
         | Is this separate from mDNS [1]? A lot of smart TVs and PCs
         | increasingly use mDNS to support some fairly handy consumer
         | features, like AirDrop, being able to setup your TV with your
         | phone, network printing/scanning, ChromeCast, whole-home
         | control of lights & other IoT devices, etc.
         | 
         | [1] https://en.wikipedia.org/wiki/Multicast_DNS
        
           | uniqueuid wrote:
           | The incident I'm referring to was about LG [1]. The report
           | includes network captures, so I'd trust it.
           | 
           | Apparently, some chinese smart TV brands have been doing
           | similar things, but I wouldn't be surprised if most other
           | vendors have caught up and used stealthier techniques.
           | 
           | [edit] Here's the news about those chinese TVs [2] and the
           | original report [3]
           | 
           | [1] https://arstechnica.com/information-
           | technology/2013/11/lg-sm...
           | 
           | [2] https://www.theregister.com/2021/05/04/skyworth_gozen_sma
           | rt_...
           | 
           | [3] https://www.v2ex.com/t/772523
        
             | excitom wrote:
             | Small point: LG is a Korean company, not Chinese.
        
               | uniqueuid wrote:
               | Right, those are two distinct incidents (and years
               | apart).
               | 
               | Sorry if that wasn't clear.
        
         | jacquesm wrote:
         | Iirc the ebay thing was yet another way to fingerprint you to
         | re-identify fraudulent account creators.
        
         | swiley wrote:
         | That's a clear violation of the CFAA. This crime carries prison
         | time. How come they threw teenagers in prison but not the
         | people responsible for doing it en mass?
        
           | the_mitsuhiko wrote:
           | How is this a violation against the CFAA?
        
             | swiley wrote:
             | Unauthorized network access? Literally the whole point of
             | the thing.
        
               | Hnrobert42 wrote:
               | I would argue the point was the opposite. It began with a
               | request for authorization.
        
               | indymike wrote:
               | > It began with a request for authorization.
               | 
               | Yes, by asking someone who doesn't have permission to
               | give that authorization to do so.
        
               | swiley wrote:
               | I don't see how this is any different than walking into a
               | building and telling the concierge you're a maintenance
               | worker.
        
               | 73r7fudhdjduru wrote:
               | The illegal part there isn't requesting access it's lying
               | about being a maintenance worker to gain access.
        
               | [deleted]
        
               | kayfox wrote:
               | What access controls are being bypassed?
        
           | na85 wrote:
           | There are a different set of laws for me and you.
           | Corporations and CEOs play by their own rules.
        
           | judge2020 wrote:
           | If it's a clear violation maybe sue them for breaching your
           | network?
        
             | swiley wrote:
             | I don't even have non-free mobile OSes on my network much
             | less this.
        
           | teawrecks wrote:
           | Because people blindly accept terms of service.
        
             | xvector wrote:
             | It's not people's fault that terms of service are
             | intentionally designed to be as long-winded as possible if
             | you want any hope of using a product or service.
        
         | hipsterhelpdesk wrote:
         | It only "leaks" your ip if you are trying to use webrtc
         | features with a vpn, otherwise web rtc is perfectly fine to use
         | without concern for most people.
        
           | uniqueuid wrote:
           | Interesting! That's not how I read the ublock origin docs:
           | 
           | "Keep in mind that this feature is to prevent leakage of your
           | non-internet-facing IP adresses. The purpose of this feature
           | is not to hide your current internet-facing IP address -- so
           | be cautious to not misinterpret the results of some WebRTC-
           | local-IP-address-leakage tests found online."
           | 
           | That said, my Firefox 91 and Safari don't leak local IPs
           | regardless of the ublock setting.
           | 
           | Warrants more investigation perhaps.
        
             | allo37 wrote:
             | I believe newer versions of WebRTC use mdns to mask local
             | IPs:
             | 
             | https://bugs.chromium.org/p/chromium/issues/detail?id=87846
             | 5
        
               | uniqueuid wrote:
               | Great find! Here's the IETF draft [1], submitted by Apple
               | (which would explain why I'm not seeing leaks on Safari)
               | 
               | [1] https://datatracker.ietf.org/doc/html/draft-mdns-ice-
               | candida...
        
         | wyager wrote:
         | Many common wifi APs (eg TP-link EAP225) will allow you to
         | create separate wifi networks on different VLANs. You can use
         | this to isolate internet of shit devices onto their own
         | networks where they can't talk to your other devices, without
         | increasing your hardware costs or causing wifi interference.
         | 
         | You'll need a router/firewall and an AP that are both VLAN-
         | aware. I personally use an EAP225 and some eBay industrial PC
         | running freebsd.
        
           | blacksmith_tb wrote:
           | And/or some routers offer 'AP Isolation' or 'Client
           | Isolation' to prevent devices from communicating with each
           | other (I am always glad to see public networks configured
           | this way, but at home it'd be a pain to not be able to shell
           | from one box into another etc.)
        
       | the_mitsuhiko wrote:
       | For some technical context: this dialog pops up the first time an
       | app attempts to send a packet to a local device. A "common"
       | reason why this happens are actually your own network devices if
       | you're connected on wifi. For instance sending a custom DNS query
       | to the wifi advertised DNS server (if it's the router) will cause
       | that dialog. Same thing happens if you happen to have a router
       | redirect certain resources to itself. The latter typically at
       | this point only happens for non encrypted HTTP traffic and that's
       | basically no longer permitted.
       | 
       | So why it happens exactly would be interesting.
        
         | nicce wrote:
         | More context, especially resolving link-local DNS names (those
         | ending with local, per RFC 6762) requires local network access.
         | For iOS devices, Apple has summed this pretty well[1]. Yes, if
         | permission required on below:                   Making an
         | outgoing TCP connection -- yes              Listening for and
         | accepting incoming TCP connections -- no              Sending a
         | UDP unicast -- yes              Sending a UDP multicast -- yes
         | Sending a UDP broadcast -- yes              Receiving an
         | incoming UDP unicast -- no              Receiving an incoming
         | UDP multicast -- yes              Receiving an incoming UDP
         | broadcast -- yes              And finally usage of Bonjour
         | operations.
         | 
         | [1] https://developer.apple.com/forums/thread/663874
        
         | uniqueuid wrote:
         | Thanks for the details!
         | 
         | That opens new questions; for example, what's a "custom" DNS
         | query? One that doesn't use mDNSResponder (or whatever iOS uses
         | right now)?
        
           | the_mitsuhiko wrote:
           | I am not sure under which circumstances it flags. If you
           | write your own DNS client for sure it will happen, but there
           | seem to be more things that cause this to trigger.
           | 
           | After that dialog was introduced I saw it pop up on stack
           | overflow for some relatively common libraries (for instance
           | with unity) even if they did not attempt to access the local
           | network.
        
         | stingraycharles wrote:
         | Interesting. I initially denied the permission, but Tiktok
         | seemed to not be able to make any Internet requests. The kind
         | of behavior I would expect if DNS didn't work anymore.
         | 
         | Maybe it's just as innocent as this, but OTOH, it's tiktok
         | we're talking about.
        
       | intrasight wrote:
       | So just use their web site. Honest question - why do people use
       | apps for such?
        
         | finiteseries wrote:
         | Because that's how <insert app> is used. The concept of apps
         | and web sites being separate things, or being different, or
         | preferable to one another isn't on the radar of 95% of people,
         | it's a blurry shapeless vagueness the mind glazes over if it's
         | ever forced into recognizing its existence, and immediately
         | discarded afterwards.
         | 
         | You're asking a forum of power users/creators, where a loud
         | minority completely unironically still use desktop & laptop
         | computers for activities besides work. The only people on earth
         | less understanding (intentionally or not) of consumer behavior
         | are the Sentinelese.
        
           | JadeNB wrote:
           | > a loud minority completely unironically still use desktop &
           | laptop computers for activities besides work.
           | 
           | Is using a desktop or laptop for non-work activities ironic
           | somehow?
        
             | finiteseries wrote:
             | I honestly don't know what exactly irony means.
             | 
             | unironically = sincerely/earnestly
        
               | JadeNB wrote:
               | Right; I wasn't playing grammar gotcha. I use my laptop
               | for non-work activities, and I guess I do so sincerely.
               | Do people use their laptops or desktops for non-work
               | activities somehow insincerely?
        
               | finiteseries wrote:
               | Sure, for example as a last resort when your phone or
               | whatever has died, but the charger is _over there_ , ugh.
        
         | cblconfederate wrote:
         | You mean you don't like being spied on?
        
         | mzs wrote:
         | For IG the web site pales in comparison. I don't use the app
         | but I have an account courtesy FB I think and all the
         | recommendations are "Instagram recommended" accounts like pop
         | singers and reality TV stars even after I followed some that
         | weren't such as in real world friends and family. There's no
         | way to discover other interesting material. So I guess it's
         | because the web version can be much worse.
        
         | mdoms wrote:
         | I think it's very unlikely that Tiktok could build an
         | equivalent UX that would work in a browser, including the
         | creators tools. And even if they could - have they done so?
         | 
         | And let's not forget that Apple actively works against this way
         | of working by intentionally gimping their browser capabilities
         | and outright disallowing competing browsers.
        
         | mattnewton wrote:
         | Because these services usually do not develop their websites to
         | parity with their apps and push users heavily to install apps.
        
         | micromacrofoot wrote:
         | On mobile they heavily push people to the app... this is the
         | answer to most "just use the website" questions. Reddit mobile
         | has been particularly bad about this lately, by blocking
         | content. Instagram hits you with a login gate after viewing a
         | few photos, etc... all of these companies are pushing their
         | users to the place where they can siphon off the most data,
         | which at the moment are apps.
        
       | prashnts wrote:
       | Curiously, I have seen this prompt in apps that did not normally
       | ask for this permission when I was on a captive network without
       | having logged in. No idea why it was prompted, but could be
       | related somehow?
        
       | j45 wrote:
       | Instagram is requesting access to local devices on the network as
       | well as of yesterday.
        
       | donohoe wrote:
       | Twitter does it too
       | 
       | https://twitter.com/donohoe/status/1412563187426369537
        
       | dangoor wrote:
       | Perhaps there's something nefarious here, or perhaps it's just
       | looking for a Chromecast or Apple TV?
        
         | SllX wrote:
         | You no more need Bluetooth permissions to use AirPlay than you
         | do to for AirPods because the OS is deciding the output device
         | per the users instructions[1].
         | 
         | Also: TikTok doesn't support AirPlay or Chromecast.
         | 
         | [1] Per the user's instructions on a _good_ day at least.
        
         | dehrmann wrote:
         | I saw the same message yesterday from Spotify when I tried to
         | use Chromecast. At least it prompted me for the permissions
         | when I took that action, so it was clear why.
        
           | zahrc wrote:
           | Which is usually only when it appears - when I specifically
           | request the app to do something which requires to scan for
           | local devices.
           | 
           | Tiktok doesn't support chrome cast (I think)
        
         | Lammy wrote:
         | Any discussion of intent is always going to be speculation. All
         | we can think about is what such a thing would be capable of if
         | it were somehow malicious.
         | 
         | The first possibility that comes to my mind would be sniffing
         | Ethernet MAC addresses because it could be done without any
         | sort of device-specific support built in to the app. Assuming
         | your local devices' manufacturers are following Da Rulez, the
         | first part of their MAC address usually tells you the company,
         | and the second part tends to be individualized/serialized.
         | 
         | That would, for example, let TikTok derive when certain users
         | are together IRL if they both show up scan-adjacent to a unique
         | MAC. Or maybe it could let them derive multiple accounts
         | belonging to a single person if one is used on VPN-only to
         | discuss political or personal topics that person might not want
         | associated with their IRL identity.
        
           | giantrobot wrote:
           | If I was a state intelligence service I would _love_ TikTok.
           | Especially if it was legally banned in my country so was used
           | almost exclusively by foreigners. One better was if the
           | government had a controlling stake in the company [0] and
           | laws requiring the company to be virtually transparent to
           | demands from state security agencies [1].
           | 
           | Not only does TikTok have a ton of overt data about users but
           | also contemporaneous data like usage patterns and physical
           | location. Then using the app to collect and exfiltrate
           | information about all manner of foreign networks. I can pass
           | off that data to my government run hacking [2] groups [3] as
           | well as regime-favored businesses for some really great
           | market research.
           | 
           | [0] https://finance.yahoo.com/news/bytedance-says-china-unit-
           | hol...
           | 
           | [1] https://en.m.wikipedia.org/wiki/Cybersecurity_Law_of_the_
           | Peo...
           | 
           | [2] https://en.m.wikipedia.org/wiki/PLA_Unit_61398
           | 
           | [3] https://en.m.wikipedia.org/wiki/PLA_Unit_61486
        
           | sam0x17 wrote:
           | You can also just take the collection of devices typically on
           | the network, hash the MAC addresses all together, and now you
           | have a unique identifier for a household
        
             | vineyardmike wrote:
             | has the mac's and use a bloom filter, look for overlaps
             | across time/accounts.
        
             | ALittleLight wrote:
             | But devices would join and leave the network in a household
             | - especially phones. Maybe you could have a listening
             | period, e.g. a week, where you build a set of witnessed
             | devices and then hash that for a household id?
        
           | rafale wrote:
           | Can you send packets to local network if you are using a VPN
           | on ur phone? Sounds like a VPN bug to me.
        
             | oefrha wrote:
             | Of course you can. Look up VPN routing / split tunneling.
             | It's not uncommon for corporate VPNs to only route intranet
             | traffic for instance; and LAN is usually whitelisted.
        
               | MichaelGroves wrote:
               | Besides corporate VPNs, typical consumer VPNs are also
               | set up to allow LAN access. Your average joe-smoe would
               | be annoyed if their network printer stopped working every
               | time they turned on their VPN to watch netflix movies or
               | whatever.
        
               | oasisbob wrote:
               | IPSEC VPNs (and others) have the remote networks defined
               | in the protocol as part of the security association (SA).
               | The SAs define which networks are available over the
               | tunnel.
               | 
               | Saying "all RFC1918 addresses are available over here" is
               | quite a cocky and obviously broken thing to do, unless
               | you're dealing with a corporate device which is paranoid
               | about leaking traffic to other networks.
        
               | oefrha wrote:
               | Yes, "LAN is usually whitelisted" in my comment is
               | independent from the corporate split tunneling example.
        
           | dheera wrote:
           | Apple is also complicit in making it incredibly hard to
           | execute an MITM proxy to know what your iOS apps are sending
           | back to their servers.
           | 
           | Being able to MITM and see what your apps and OS are sending
           | back is the first step to real privacy.
        
         | xfitm3 wrote:
         | Assuming this is iOS doesn't the native screen sharing
         | capability handle that?
        
           | mholm wrote:
           | Not chromecast.
           | 
           | My charitable guess is they're adding support for
           | chromecasting behind feature flags/AB testing, but don't yet
           | have it correctly enabled/disabled. There was a lot of uproar
           | over instagram immediately using the microphone/camera
           | constantly, when they actually just always had the API
           | initialized to make swiping to the camera snappier.
        
             | danudey wrote:
             | That could also explain why they didn't bother to provide
             | in the notification to the user _why_ they 're requesting
             | this access: because they weren't intending to request it
             | (yet).
             | 
             | I find the conspiracy theories more compelling, but less
             | likely.
        
               | toxik wrote:
               | When an app tells you it's stealing your data, I would
               | say you should believe it.
        
         | mercora wrote:
         | it would be a little too obvious if this is done for nefarious
         | reasons by TikTok developers themselves.
        
           | mtgx wrote:
           | Why too obvious? 99% of people don't pay attention to this
           | stuff. Look at what Facebook has been doing to users for
           | years and years before being caught and blaming it on a bug
           | or becoming way to familiar to Britney's lyrics in "Oops, I
           | did it again."
        
         | Maxburn wrote:
         | I don't see chromecast or apple tv called out as a capability,
         | and I'm not installing it to find out. I also don't really see
         | the LAN access reasons there either.
         | https://apps.apple.com/us/app/tiktok/id835599320
         | 
         | https://play.google.com/store/apps/details?id=com.ss.android...
         | 
         | Based on the things they do call out as permissions this app is
         | scary.
        
         | starik36 wrote:
         | TikTok doesn't have either feature. At least I don't see an
         | obvious way to connect.
        
         | Closi wrote:
         | Yeah, although I can't think of an immediate use-case
         | considering Tiktok doesn't support streaming to Chromecast or
         | Apple TV.
        
         | SavantIdiot wrote:
         | If it only connects to multimedia devices, and if my OS lets me
         | know that TikTok is using my multimedia devices, then I'd be OK
         | with it, but I don't TikTok. Like MicroSnitch, which warns you
         | when a mic/camera becomes active (macOS only).
        
         | hatware wrote:
         | Trusting companies not to abuse the simple explanation of
         | Chromecast is dead in the water, though. Why on earth would you
         | trust a company _not_ to abuse that?
        
         | azinman2 wrote:
         | If this just start popping up and without an explanation
         | string, my guess is they included some 3rd party SDK that is
         | doing fingerprinting on the local LAN, much like FB SDK's used
         | to do.
        
       | uniqueuid wrote:
       | Microsoft Teams does this as well, purportedly for video calling
       | (!?) Was there ever an explanation why the permissions are
       | needed?
        
         | uniqueuid wrote:
         | Just did a quick search and found that teams does in fact
         | support some sort of local-only streaming:
         | 
         | https://docs.microsoft.com/en-US/microsoftteams/use-ndi-in-m...
         | 
         | I do trust Microsoft to collect all tracking data that's
         | possible at all, but at least there is _also_ a valid use case
         | here.
         | 
         | It's even somehow plausible that they would require this
         | permission for any kind of video streaming - to make sure all
         | permissions are present _before_ someone wants to start a
         | locally streamed call.
        
         | avnigo wrote:
         | I assumed it was to gracefully deal with handoff from one
         | device to another while in a meeting since you can start on one
         | device and continue with another, or maybe to share your screen
         | from another device etc. It would be nice to know why exactly
         | certain permissions are requested; sometimes that's done by
         | telling you what feature it might break if you don't grant
         | those permissions.
        
           | uniqueuid wrote:
           | That's a great observation - for handoff it would make much
           | more sense to get the permission beforehand, rather than
           | trying to stop all sorts of a/v and network processes to get
           | the user's ok.
        
         | mschuster91 wrote:
         | It saves Microsoft traffic if people are in the same office
         | building / corporate VPN and can exchange audio/video streams
         | directly vs having to go through a MS-provided STUN/TURN
         | intermediate server.
        
         | lloydatkinson wrote:
         | For MS I suspect either incompetence or laziness and just
         | checking all the permissions (because a lot of Teams seems
         | poorly thought out and designed by committee, probably an
         | "agile" one too).
         | 
         | As for Tick Tock it's obviously spyware meant for direct user
         | identification. How anyone can use it when it's uploading their
         | biometric information (face, voice) to the CCP is beyond
         | stupidity.
        
           | andrewmd5 wrote:
           | It is to support finding devices you can cast to inside the
           | app (like conference calling boxes.)
        
           | po1nter wrote:
           | It's TikTok* and do you have any evidence to support what
           | you're saying or you're just pulling this from thin air?
        
             | filoleg wrote:
             | So far from what I've seen, it is mostly along the lines of
             | "they technically can, so I assume they do."
             | 
             | Even when it comes to someone like me, who is very strongly
             | anti-CCP, it definitely irks me a bit. Mostly because
             | making strong accusations like that without any reasoning
             | other than "they can, so they definitely do it" only makes
             | that position look weaker and more difficult to align with.
             | Why make up those things and accusations, when there are so
             | many other valid points for criticism there? There is a
             | reason for why "the boy who cried wolf" is a very commonly
             | referenced parable.
        
       | micromacrofoot wrote:
       | Don't forget that TikTok is also currently under investigation by
       | the US secretary of commerce to determine whether or not it's a
       | threat to national security.
       | 
       | Are people getting enough out of the content on TikTok to warrant
       | installing an app from a country that has been outright hostile
       | to the US (from a cybersecurity perspective)?
       | 
       | I've seen some of the most popular TikTok content without ever
       | creating an account.
        
       | abledon wrote:
       | This is only the TikTok iOS/Android app right? Not the web app?
        
         | throw03172019 wrote:
         | Yes, iOS app in this specific case.
        
       | rvz wrote:
       | Why does TikTok 'need' access to devices on your local network?
       | 
       | The intention from YouTube is obvious as they use it for
       | Chromecast, but why does TikTok need this particular access? Have
       | they disclosed this usage somewhere?
       | 
       | On top of that and continuing from [0], it seems that it is
       | collecting even more things that you may not even know about [0].
       | Far worse than the other apps out there.
       | 
       | The purpose? The recommendation algorithm, of course. Otherwise,
       | how else is it supposed to work?
       | 
       | To Downvoters: Lots of commenters here saying that TikTok does
       | not support AirPlay or Chromecast. Since that can be ruled out,
       | what is the intention of this permission and is it disclosed
       | anywhere on why do they need such access?
       | 
       | I'm also assuming that you know why TikTok needs access to
       | devices on your local network? Maybe you can elaborate on this?
       | 
       | [0] https://news.ycombinator.com/item?id=28137000
        
       | jeffbee wrote:
       | There are two ways that the TikTok mobile app can be used to
       | control the app running on a smart TV, android TV, roku, or
       | whatever.
       | 
       | 1) The app on the smart tv can connect to a command-and-control
       | network in the cloud, which will make deranged HNers howl in
       | disapproval.
       | 
       | 2) The app on the phone can discover local devices it can
       | control, which will make deranged HNers howl in disapproval.
        
       | snapetom wrote:
       | Pokemon Go started asking for this back in March with an update.
       | I don't think it was ever figured out why it would want access,
       | and it's certainly not for Chromecast/Roku/AppleTV.
        
         | SllX wrote:
         | Pokeball Plus support. I mean, I can't speak to Niantic
         | fingerprinting players because I don't know if they are, but
         | you do need Bluetooth to use the Pokeball Plus properly. Also I
         | believe you need Bluetooth to work with the Let's Go Pikachu
         | and Eevee games on the Switch to transfer Pokemon back and
         | forth, but I never did get that to work properly.
        
           | snapetom wrote:
           | Yeah, but Let's Go and Pokeball were released years ago. Go
           | Plus was released almost Day 1, if I recall. All of those
           | connect via Bluetooth and never required a network. They all
           | still work just fine if you deny PoGo the permission to
           | access devices.
        
             | SllX wrote:
             | Correct me if I'm wrong, but isn't this the same dialog
             | that pops up for Bluetooth devices or am I missing
             | something?
             | 
             | I haven't used my Pokeball Plus since about a month after I
             | bought it, which was basically day or week 1, but if I
             | recall correctly the mandate to ask for permissions only
             | came around after that time frame and I would expect it the
             | next time I pulled it out.
             | 
             | But if it does work without Bluetooth permissions; then
             | that's cool, or if this is a separate dialog than the
             | Bluetooth permissions dialog, then I'm just wrong which is
             | also fine and I can live with that.
        
       | Dragging-Syrup wrote:
       | Straight to the IOT isolation network
        
         | moooo99 wrote:
         | Your phone?
        
           | MisterTea wrote:
           | I mean if its being hostile to your LAN then why not?
           | 
           | Let the hostile phones, TV's, sonos, toasters, etc live on
           | the IOT network and your laptop, desktop, NAS and whatever
           | else you value live on a your actual LAN.
        
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       (page generated 2021-08-16 23:00 UTC)