[HN Gopher] Zero click vulnerability in Apple's macOS Mail
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       Zero click vulnerability in Apple's macOS Mail
        
       Author : jviide
       Score  : 138 points
       Date   : 2021-04-01 19:03 UTC (3 hours ago)
        
 (HTM) web link (mikko-kenttala.medium.com)
 (TXT) w3m dump (mikko-kenttala.medium.com)
        
       | petra wrote:
       | Is it true that Apple devices are more secure than good Android
       | devices(like Google's Pixel)?
       | 
       | Or is it just security theater ?
        
         | als0 wrote:
         | As far as what is feasible, Apple does a very good job with
         | their iPhone/iPad security. With both hardware and software.
         | You can read about it how it all works in their platform
         | security guide.
         | 
         | On the Android side, Google makes good software changes to
         | Android, but ultimately the security is dependent on the
         | handset maker (e.g. Samsung) and SoC maker (e.g. Qualcomm).
         | Security will vary between Android phones. The bigger Android
         | phone makers are more able to make security investments than
         | the cheaper phone makers.
        
         | rogerbinns wrote:
         | A big difference is that the software running on Apple devices
         | is less complex. For example there is significantly less
         | hardware support. iMessage only talks to other iMessage
         | instances (eg no browser support). There is only one web
         | browser engine. Third party apps can't do JIT code generation.
         | Older APIs are actively removed, breaking existing apps (vs
         | providing backwards compatibility).
         | 
         | In general less complexity is better, but it also constrains
         | things. For example it took until recently for third party iOS
         | to be able to do NFC. Android had it since ~2012.
        
           | wunderflix wrote:
           | _> Android had it since ~2012._
           | 
           | I seriously wonder: what difference did it make? Was there
           | any groundbreaking thing iOS users missed for 8 years?
           | 
           | Apple is just great in omitting things and keeping focus to
           | deliver a great product and then expand on that basis.
           | 
           | Most famous example: First iPhones didn't have MMS
        
             | musicale wrote:
             | > First iPhones didn't have MMS
             | 
             | Or cut and paste. ;-)
        
             | toxik wrote:
             | MMS is whack though
        
             | musicale wrote:
             | "No wireless. Less space than a nomad. Lame."
        
         | tempfs wrote:
         | Apple's entire business model is based on appearances. To be
         | fair so is Microsoft's and many others.
         | 
         | Security is usually the last priority for nearly every for
         | profit entity because it doesn't drive revenue.
        
           | willio58 wrote:
           | Security drives profit if it is marketed well. Apple does
           | this. Think about even their branding for certain things,
           | e.g. "Secure Enclave".
        
           | etaioinshrdlu wrote:
           | Apple puts rather extreme security effort into preventing iOS
           | jailbreaks. They are pretty serious about trying to prevent
           | data exfiltration from locked iOS devices as well.
           | 
           | They aren't perfect but I don't think it's fair to say they
           | don't try.
        
             | viraptor wrote:
             | I wouldn't call it extreme when there was a known public
             | website allowing one-click jailbreak for good few months
             | (not sure if it was actually ever patched or just the iOS
             | version got eol)
        
               | _underfl0w_ wrote:
               | They then hired the guy creating those exploit chains.
        
               | ghughes wrote:
               | 10 years ago, yeah.
               | 
               | https://en.m.wikipedia.org/wiki/JailbreakMe
        
         | 2OEH8eoCRo0 wrote:
         | >While the police managed to crack into Wong's iPhone, which
         | was locked with a four-digit passcode, they did not manage to
         | access the contents of Chow's Google Pixel phone using the
         | force's existing digital forensics tools, according to the
         | court filing. Chow says her phone is still in police
         | possession.
         | 
         | https://qz.com/1844937/hong-kongs-mass-arrests-give-police-a...
        
           | [deleted]
        
         | codemac wrote:
         | If you turn on iCloud, it's theater.
         | 
         | Android with syncing enabled does much better in real world
         | tests. Notably in hong kong, they were able to crack the
         | iPhones, but not the Pixels[0]
         | 
         | I'm pretty sure without iCloud and a long enough password (or
         | fast enough self destruct mode) iPhones could be as secure, but
         | I don't know anyone that uses an iPhone and does not use iCloud
         | in any way.
         | 
         | [0]: https://qz.com/1844937/hong-kongs-mass-arrests-give-
         | police-a...
        
         | viraptor wrote:
         | I like the way (I think) the grugq described it: out of the box
         | iPhones are great with security, but Android allows you to
         | build / get better yourself. See the copperhead project for
         | example https://copperhead.co/android/
        
       | asddubs wrote:
       | good old symlinks, always wreaking havoc
        
       | threatofrain wrote:
       | > 2020-05-16: Issue found
       | 
       | > 2020-05-24: PoC done and reported to Apple
       | 
       | > 2020-06-04: Catalina 10.15.6 Beta 4 with [hotfix released]
       | 
       | > 2020-07-15: Catalina 10.15.6 Update with hotfix released
        
         | lehi wrote:
         | > 2021-03-30: Bug Bounty is still being evaluated
        
           | marshmallow_12 wrote:
           | If Apple are actually serious, why are they taking so long to
           | give the bounty? It's sounds like madness to me.
        
             | stephc_int13 wrote:
             | This is clearly what triggered the post.
             | 
             | Work was done but not paid. Shitty business on Apple
             | side...
        
           | MuffinFlavored wrote:
           | The company has billions of dollars. I don't think a
           | $50k-$100k bug bounty payout for them is a big deal. Even $1m
           | wouldn't be a big deal to them.
        
       | swiley wrote:
       | It's hardly surprising, you can run into memory corruption bugs
       | just using desktop mail.app the way it's intended (there's been a
       | bug that corrupts the account list for probably a decade which
       | just hasn't been fixed.)
       | 
       | Mutt may _look_ old but at least it actually works.
        
       | Zhenya wrote:
       | It seems backwards that Apple acknowledges the issue, PATCHES it,
       | but still hasn't paid out.
       | 
       | Maybe a good business is bug escrow company.
        
         | hbbio wrote:
         | zerodium
        
       | _alex_ wrote:
       | That's gonna be devastating to the three people who use Mail.app
        
         | gumby wrote:
         | I switched to it with the first release of OS X and have been
         | pretty happy with it.
         | 
         | Amazingly I have a handful of messages from the late 70s (a
         | couple of jokes and a couple of personal messages from friends
         | who passed away young) that have survived the file format
         | transitions since then but I couldn't imagine could appear in
         | something like google or yahoo mail. TBH I haven't made that
         | many transitions: EMACS (BABYL) on ITS, then TOPS-20; Interlisp
         | and Smalltalk clients to Grapevine back end; Lispm to TOPS-20
         | back end; GNU Emacs (rmail?) to IMAP; and then Apple Mail
         | (macOS and iOS) -> IMAP. Emacs is the most powerful but these
         | days still hard to put in your pocket.
         | 
         | In general a web browser seems like the _worst_ interface to
         | most services and activities as the UI can 't be dedicated to
         | the task at hand; instead you have system UI, Browser UI and
         | only then the application UI. And a lot of mouse activity is
         | expected.
        
         | stock_toaster wrote:
         | ;_; one of us. one of us.
         | 
         | Whats a good alternative for macos these days? I loved sparrow
         | back in the day, before I got acquired and killed by google.
        
           | djxfade wrote:
           | I personally love Mimestream. Its a native Gmail client
        
           | _alex_ wrote:
           | Mailmate is pretty awesome
        
         | politician wrote:
         | With the Mail.app pegging their CPU to 100%, those three people
         | are unlikely to notice. Frankly, it's unlikely for the attacker
         | to be able to do anything either, aside from force-terminating
         | Mail.app.
         | 
         | (Disclaimer: I want to like Mail.app, but I don't need another
         | fan in my office.)
        
           | [deleted]
        
           | oleganza wrote:
           | I'm using Mail.app since 2007 when i switched to Mac and
           | never had issues other than a couple of times around 2009-10
           | when it had sync problems with Gmail. -\\_(tsu)_/-
        
           | codezero wrote:
           | The post indicated that the attacker can change the
           | configuration, filters, as well as forwarding rules (exfil),
           | this doesn't seem terribly benign.
        
         | veselin wrote:
         | A new Mac comes with something like 30 apps in the bar. I
         | clicked and disabled every single one of them except Finder and
         | used Safari to download another browser. If it was any other
         | manufacturer, this mess would be quickly denounced by reviewers
         | as crapware. But because it is by Apple, it is not a problem at
         | all.
         | 
         | I am not expecting this to fix by itself. Maybe some major
         | review blogs should first not parrot how magical the whole
         | thing is and change the tone as such things are not only
         | annoying, but also a security risk even if you don't actively
         | use the app. I am not an expert on development for MacOS, but I
         | would be surprised if there is no way to trigger the mail app
         | from another app or a link. I just hope the bug is not
         | exportable this way.
        
           | Aloisius wrote:
           | I'm not sure I could classify any of 23 items in the default
           | dock as as crapware.
           | 
           | None are demos or trialware. Hell, I use all of them except
           | for FaceTime, Podcasts, Pages, TV and Launchpad.
           | 
           | I do remove most of them from the dock since I use spotlight
           | to launch things, but removing System Preferences from my
           | dock hardly makes it crapware.
        
           | blacksmith_tb wrote:
           | I assume you mean the Dock? I am with you there, on a new
           | install of macOS I drag pretty much all their apps out of it
           | (to be fair, I do the same thing on a new Ubuntu desktop
           | install too...). Of course in a sense the Dock is an
           | anachronism, I find it useful once in the while to drag a
           | file onto an app there, but generally for launching apps I
           | prefer Spotlight (actually Alfred).
        
         | ratww wrote:
         | That's not what the statistics say:
         | 
         | https://emailclientmarketshare.com
        
           | wahern wrote:
           | Wow, Mail.app has more market share than Outlook. I'm
           | pleasantly surprised. Ditto for GMail only having ~30%.
           | 
           | Although,
           | 
           | > Since determining the client in which an email is opened
           | requires images to be displayed, the data for some email
           | clients and mobile devices might be over- or under-
           | represented due to automatic image blocking.
           | 
           | Outlook doesn't display external images by default, while
           | Mail.app does, so....
        
             | uberduper wrote:
             | As far as I know and recall from the years I've been using
             | Mail.app, it does not download external images by default.
        
               | wahern wrote:
               | It does. I even provided a citation several weeks ago in
               | another thread, though a quick Google search seems to
               | bring up ample support of its own.
               | 
               | Like me you may have disabled it and forgotten. Whenever
               | I get a new laptop at work I tend to go through and
               | change all the defaults, such as reverting to plaintext
               | composition, and habitually disable external image
               | loading as part of the process.
               | 
               | The iPhone Mail app may have saner defaults, however, but
               | I don't have an iPhone and have never used its e-mail
               | client.
        
             | zakki wrote:
             | Does Apple excluded Mail.app from their privacy focused
             | strategy?
        
             | iamacyborg wrote:
             | Also, I assume there's a different demographic that uses
             | Mail vs Outlook. Those different demographics will receive
             | different types of email, which may or may not be
             | represented differently by companies who use Litmus
             | tracking which is how this data is being collected.
        
             | cozzyd wrote:
             | right, neither does Evolution or Thunderbird. It's crazy
             | that Mail.app does this.
        
           | uncledave wrote:
           | Am I the only one using outlook and loving it?
        
             | fullwaza wrote:
             | Yes
        
             | munk-a wrote:
             | No - I still don't like it myself but they've made some
             | pretty great strides in feature parity and have excellent
             | integration if you're a Teams shop.
        
             | roym6 wrote:
             | Outlook on Mac consumes outrageous amounts of ram...
        
               | darkwater wrote:
               | Absolutely. Mail.app on Windows instead is pretty
               | lightweight /s
        
             | LegitShady wrote:
             | its gotten better but its still not great.
        
           | mhh__ wrote:
           | I'm surprised how high the iPhone share is. Specifically in
           | light of it usually being stated in any thread discussing
           | apple and regulation that Apple do not have anything close to
           | a controlling share of the market
        
         | kps wrote:
         | What are the options for those who foolishly installed an OS
         | version later than Snow Leopard and can't run Eudora?
        
           | Someone wrote:
           | Porting the Mac version to a modern Mac OS will be a serious
           | challenge, but source code is available (BSD-licensed). See
           | https://computerhistory.org/blog/the-eudora-email-client-
           | sou....
        
         | wahern wrote:
         | The feature accretion and default layout redesigns have
         | increasingly become a headache, but Mail.app still seems like
         | the spiritual successor to Eudora, which may have remained the
         | most popular desktop e-mail GUI if Microsoft hadn't leveraged
         | their monopoly in the business workstation and LAN markets to
         | push the adoption of Outlook. I use mutt for personal e-mail,
         | but prefer Mail.app for work.
        
         | rvz wrote:
         | Your comment is about to become dead. I'll preserve the context
         | here:
         | 
         | > That's gonna be devastating to the three people who use
         | Mail.app
         | 
         | Multiply that by 100,000,000
        
         | codezero wrote:
         | It's my main email client, what's wrong with it?
        
           | tasogare wrote:
           | What's right with it? I tried it a few times and always
           | returned to web-based clients (on desktop) and third-party
           | apps (outlook, gmail, protonmail) on iOS.
        
             | techbubble wrote:
             | I find it works very well, so basically everything seems
             | right. Use it for nine accounts concurrently. Rarely have
             | any issues.
        
             | duiker101 wrote:
             | So what's wrong with it?
        
             | sixstringtheory wrote:
             | What web-based client will allow you to read email without
             | an Internet connection in Safari?
             | 
             | What marginal advantage does a third-party iOS client
             | provide, that outweighs the risks of installing another app
             | that is going to spy on me, have weaker integration with
             | the OS and force me to relearn every new UI design language
             | they come up with that in no way resembles the rest of the
             | OS or its function and behavior?
        
             | Aloisius wrote:
             | Web gmail sucks when you have multiple accounts.
        
         | sneak wrote:
         | I am one of those three people. Do you know of any decent gui
         | IMAP clients?
        
           | _alex_ wrote:
           | I like Mailmate
        
             | sneak wrote:
             | If I switch, it will need to be to something that works on
             | more than just macOS, and nonfree software will be excluded
             | from consideration.
        
       | igammarays wrote:
       | Ok, remind me never to approach Apple directly if I happen to
       | find a vulnerability. Zerodium (or a 3-letter agency) it is!
        
         | mhh__ wrote:
         | > 3-letter agency
         | 
         | From the wikipedia page for Meltdown: "On 8 May 1995, a paper
         | called "The Intel 80x86 Processor Architecture: Pitfalls for
         | Secure Systems" published at the 1995 IEEE Symposium on
         | Security and Privacy warned against a covert timing channel in
         | the CPU cache and translation lookaside buffer (TLB). This
         | analysis was performed under the auspices of the National
         | Security Agency's Trusted Products Evaluation Program (TPEP)."
         | 
         | i.e. did they know even in 1995?
        
           | vmladenov wrote:
           | My understanding is that people at the time were aware of
           | potential problems but no vulnerability had been identified.
           | I found some discussion here:
           | https://security.stackexchange.com/a/177256
        
         | gruez wrote:
         | Is this referencing the slow turnaround time, or the lack of a
         | bounty paid so far? If it's the latter, I think it's already
         | well known that bug bounties pay far less than the "market"
         | value of such exploits.
        
           | igammarays wrote:
           | > well known
           | 
           | Well I didn't know, until now. I saw the bug bounty page at
           | Apple before, was dazzled by the numbers, and didn't think
           | twice about approaching them if I found a bug. Now after this
           | article I know better than to trust them to pay.
        
       | musicale wrote:
       | > Mail will parse it to find out any attachments with x-mac-auto-
       | archive=yes header in place. Mail will uncompress those files
       | automatically.
       | 
       | What could possibly go wrong? ;-/
        
       | tyingq wrote:
       | I thought macOS mail rules could also run a snippet of
       | AppleScript. Wouldn't that make this an RCE?
       | 
       | Or maybe the script has to exist in some folder this
       | vulnerability doesn't have access to?
        
         | turmio wrote:
         | Thats what I thought first too (I am the author). And your
         | guess for the reason is right. AppleScripts need to be stored
         | in ~/Library/Application Scripts/com.apple.mail directory which
         | is outside of the sandbox.
        
       | hkdobrev wrote:
       | Please don't use "zero" and "vulnerability" in the same sentence,
       | unless you mean a zero-day one. The author could have said "no
       | click vulnerability" with the same meaning. Almost caused me a
       | concern with that title! :D :D
        
         | turmio wrote:
         | Sorry about that. But thats the term what is used by Apple to
         | these type of bugs: https://developer.apple.com/security-
         | bounty/ ( Zero-click unauthorized access to sensitive data )
        
       | lupire wrote:
       | That's a terrible unzip program. Unzip Programs should not write
       | to arbitrary locations while unzipping.
        
       | microtherion wrote:
       | Thanks for an exceptionally clear writeup. Pay that person their
       | bounty!
        
         | turmio wrote:
         | Thanks!
        
       | nvahalik wrote:
       | Use MailMate!
       | 
       | https://freron.com/
        
         | LVB wrote:
         | How has maintenance & bug fixing been? I'm OK with mature apps
         | stabilizing and needing few updates, though since it is a
         | single dev with somewhat infrequent changes I thought I'd ask
         | (https://updates.mailmate-app.com/release_notes).
        
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