[HN Gopher] From object transition to RCE in the Chrome renderer
       ___________________________________________________________________
        
       From object transition to RCE in the Chrome renderer
        
       Author : mikece
       Score  : 128 points
       Date   : 2024-08-13 15:31 UTC (7 hours ago)
        
 (HTM) web link (github.blog)
 (TXT) w3m dump (github.blog)
        
       | olliej wrote:
       | I really like these super detailed exploit breakdowns, and how
       | they touch on circumventing the mitigations (largely because I
       | wish people would understand that mitigations are just that -
       | they make it harder to exploit a bug, not impossible).
       | 
       | Obviously ASLR specifically is pretty weak these days, but the
       | idea is the same (and also it's still important - this is very
       | much along the lines of "I have seatbelts why do I need airbags"
        
       | rvz wrote:
       | Haven't seen such a detailed writeup like this one in a while.
       | What a find.
       | 
       | Goes to show the level of sophistication and technical skill of
       | this RCE rabbit whole.
       | 
       | Well done.
        
       | nusl wrote:
       | Insane. I love that these bugs are being found and fixed.
        
       | gnyman wrote:
       | When did Chrome go from the most secure browser to there is a
       | exploit-chain giving RCE by visiting a malicious website every
       | second month? (Last one I recall was CVE-2024-4761 and -4671)..
       | 
       | Or maybe it was never really secure and it was just good
       | marketing?
        
         | tedunangst wrote:
         | Can't fall behind on those javascript benchmarks.
        
         | mattnewton wrote:
         | The bar for chrome was IE at the time, and it beat that.
         | 
         | I think it's also partly Google's very open culture on CVEs
         | that means they are discovered and reported on promptly. It's
         | difficult to tell how much it's just increases awareness that
         | browsers are full of holes and whether the holes are increasing
         | in size/frequency tbh.
        
         | soiax wrote:
         | It's all renderer only RCE-s, no sandbox escape. So it doesn't
         | work on your browser, only if you disable the sandbox.
        
           | js2 wrote:
           | > I then leverage this to achieve arbitrary memory read and
           | write outside of the v8 heap sandbox, and in turn arbitrary
           | code execution in the Chrome renderer process.
           | 
           | So the code is running in a process that runs as the same
           | user running the browser. That's no longer much of a sandbox
           | and you're now relying on the OS to protect your data, right?
        
             | bri3d wrote:
             | No. You're relying on the OS's sandboxing features, which
             | are much, much more granular than just "the same user
             | running the browser."
             | 
             | https://chromium.googlesource.com/chromium/src/+/HEAD/docs/
             | d...
        
             | soiax wrote:
             | No. There is a reason the author keeps repeating "arbitrary
             | code execution in the Chrome renderer process." Because
             | it's there, not in the browser process.
        
               | armchairhacker wrote:
               | https://github.com/github/securitylab/tree/main/SecurityE
               | xpl...
               | 
               | > If successful, on Ubuntu 22.04, it should call launch
               | xcalc when calc.html is opened in Chrome.
               | 
               | Then how does this work? It doesn't look like the
               | provided build flags disable any sandbox that the
               | distributed build doesn't.
        
         | helloooooooo wrote:
         | It is the most secure browser. The lifetime of these kinds of
         | bugs is generally a few weeks to perhaps 2 months. With a high
         | churn codebase, these things just happen. There is a lot of
         | ongoing work to mitigate the impact of renderer bugs, such as
         | the V8 heap sandbox.
        
         | troupo wrote:
         | As others said, they are quite open about vulnerabilities and
         | CVEs.
         | 
         | However, Chrome is an operating system unto itself. It's more
         | than 40 million lines of code comprising of complex intertwined
         | systems. It's a miracle there are so _few_ CVEs
        
         | chc4 wrote:
         | Chrome has the most vulnerabilities because it's the largest
         | browser by market share by a mile, and so has the greatest
         | number of eyes on it. You also can't extrapolate "it was never
         | really secure" from that: practically all software has bugs,
         | especially multi-million line codebases like Chrome. Relative
         | to the average C++ program Chrome is exceedingly secure, and
         | likewise Chrome has been constantly on the cutting edge of
         | introducing new security mitigations. "Is it secure" is not a
         | binary property.
        
       | infogulch wrote:
       | Google is taking hostile actions against adblockers (and has
       | attempted to do so for years now). Chrome using too much memory
       | is a meme among normies at this point. It's hard to say whether
       | Chrome is less secure than competitors or if its exploits just
       | get more publicity; clearly it was better than the competition at
       | its inception, and clearly it could be better today.
       | 
       | At what point is replacement the right answer?
       | 
       | There are some promising browser engines in development right
       | now: Servo / Verso, and Ladybird. Some discussions from the past
       | few days:
       | 
       | Verso - Web browser built on top of the Servo web engine | 806
       | points | 319 comments |
       | https://news.ycombinator.com/item?id=41215727
       | 
       | Ladybird browser to start using Swift language this fall | 200
       | points | 196 comments |
       | https://news.ycombinator.com/item?id=41208836
        
       ___________________________________________________________________
       (page generated 2024-08-13 23:00 UTC)