CVE-2011-3092

CVE: CVE-2011-3092
CWE:
- 119
- 20
bugs:
- 122337
repo: https://chromium.googlesource.com/v8/v8/
vccs:
- note: They were working on a fix for something else at the time.
  commit: 
- note: They were working on a fix for something else at the time.
  commit: 
fixes:
- note: 
  commit: 
bounty:
  amt: 1000.0
  url: http://googlechromereleases.blogspot.com/2012/05/stable-channel-update.html
  announced: '2012-05-15'
lessons:
  yagni:
    note: 
    applies: 
  question: |
    Are there any common lessons we have learned from class that apply to this
    vulnerability? In other words, could this vulnerability serve as an example
    of one of those lessons?

    Leave "applies" blank or put false if you did not see that lesson (you do
    not need to put a reason). Put "true" if you feel the lesson applies and put
    a quick explanation of how it applies.

    Don't feel the need to claim that ALL of these apply, but it's pretty likely
    that one or two of them apply.

    If you think of another lesson we covered in class that applies here, feel
    free to give it a small name and add one in the same format as these.
  serial_killer:
    note: 
    applies: 
  complex_inputs:
    note: |
      The vulnerability involved the parsing of a regular expression, which is
      a very complex language.
    applies: true
  distrust_input:
    note: 
    applies: 
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: |
      The vulnerability was largely about the interaction between native C code
      that implemented string functions, and the high-level API of Javascript. The
      fix was still in Javascript even though it was a memory corruption error.
    applies: true
  defense_in_depth:
    note: 
    applies: 
  secure_by_default:
    note: 
    applies: 
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 10008104
upvotes: 5
mistakes:
  answer: |
    The coding mistake that was made was essentially an integer overflow that
    led to miscalculating memory buffers. The mistake was not in the underlying
    native code, rather, it was misusing the C API. So the fix was actually in
    the Javascript implementation of regexp.

    The vulnerability was introduced over two commits, but really by one person
    who was working on trying to fix this boundary condition. He wasn't
    working on a vulnerability per se, but they were working on a boundary
    condition and still missed this one condition.

    For this part of V8, a lot of decisions have been made about changing what
    is handled natively and what is handled in Javascript itself. Navigating
    what exactly are the responsibilities of native code versus the built-in
    Javascript libraries is going to be the key to preventing vulnerabilities
    here.
  question: |
    In your opinion, after all of this research, what mistakes were made that
    led to this vulnerability? Coding mistakes? Design mistakes?
    Maintainability? Requirements? Miscommunications?

    Look at the CWE entry for this vulnerability and examine the mitigations
    they have written there. Are they doing those? Does the fix look proper?

    Use those questions to inspire your answer. Don't feel obligated to answer
    every one. Write a thoughtful entry here that those ing the software
    engineering industry would find interesting.
announced: '2012-05-15'
subsystem:
  name: v8
  answer: Based on the description in the CVE and blog post.
  question: |
    What subsystems was the mistake in?

    Look at the path of the source code files code that were fixed to get
    directory names. Look at comments in the code. Look at the bug reports how
    the bug report was tagged. Examples: "clipboard", "gpu", "ssl", "speech", "renderer"
discovered:
  date: '2012-04-11'
  answer: |
    Found using LangFuzz, then reproduced by hand. Nobody was able to construct an
    exploit, but they were also not comfortable stating that an exploit was
    impossible.
  google: true
  contest: false
  question: |
    How was this vulnerability discovered?

    Go to the bug report and read the conversation to find out how this was
    originally found. Answer in longform below in "answer", fill in the date in
    YYYY-MM-DD, and then determine if the vulnerability was found by a Google
    employee (you can tell from their email address). If it's clear that the
    vulenrability was discovered by a contest, fill in the name there.

    The "automated" flag can be true, false, or nil.
    The "google" flag can be true, false, or nil.

    If there is no evidence as to how this vulnerability was found, then you may
    leave the entries blank except for "answer". Write down where you looked in "answer".
  automated: true
description: |
  The vulnerability was in Google's Javascript Engine, *V8*, in the way they
  handled regular expressions ("regexes").

  The implementation, which was in Javascript but called native C code, didn't
  handle "capture overrides" properly. This resulted in data be written to
  memory that it was not intended for (an "invalid write"). At best, this causes
  a crash. At worst, this kind of vulnerability can lead to arbitrary code
  execution as it is a "buffer overflow".

  The way that this could be exploited would be if an attacker had access to
  writing Javascript. This is possible in a Cross-Site Scripting (XSS) scenario,
  or if someone simply went to an attacker's page with Javascript that exploited
  this vulnerability.
unit_tested:
  fix: true
  code: true
  answer: |
    From looking at the fix code it's clear that code was tested and they added
    a new test for fixing this vulnerability.
  question: |
    Were automated unit tests involved in this vulnerability?
    Was the original code unit tested, or not unit tested? Did the fix involve
    improving the automated tests?

    For the "code" answer below, look not only at the fix but the surrounding
    code near the fix and determine if and was there were unit tests involved
    for this module.

    For the "fix" answer below, check if the fix for the vulnerability involves
    adding or improving an automated test to ensure this doesn't happen again.
major_events:
  answer: I did not see any major events during this time.
  events:
  - event:
      date: 
      name: 
  - event:
      date: 
      name: 
  question: |
    Please record any major events you found in the history of this
    vulnerability. Was the code rewritten at some point? Was a nearby subsystem
    changed? Did the team change?

    The event doesn't need to be directly related to this vulnerability, rather,
    we want to capture what the development team was dealing with at the time.
curation_level: 1
CWE_instructions: |
  Please go to cwe.mitre.org and find the most specific, appropriate CWE entry
  that describes your vulnerability. (Tip: this may not be a good one to start
  with - spend time understanding this vulnerability before making your choice!)
bounty_instructions: |
  If you came across any indications that a bounty was paid out for this
  vulnerability, fill it out here. Or correct it if the information already here
  was wrong. Otherwise, leave it blank.
interesting_commits:
  answer: 
  commits:
  - note: |
      They worked on changing the responsibilities between the Javascript side
      and the native side. This is pertinent because that seemed to be the
      source of the breakdown of our vulnerability in that the Javascript
      assumed the native code had more checks than it did. Following up and
      reading the code review, they reference "offline" discussions - so this is
      probably mostly a co-located team within Google.
    commit: 1729e3c0ddf0c7a0f912ef38355d38afe284bf04
  - note: |
      They worked with some memory management issues on the native code in this
      commit. No code review for this change, but it was a very large change on the
      native side, with some changes on the Javascript side.
    commit: 0f682143d9a50441188ae09cbd669f5389e44597
  - note: |
      Tons of code removed for this commit, related to how caching works. No
      rationale was obvious from the documents, but it was a very significant
      change code-wise.
    commit: e1458503d13cbcc20ae619a1a4d6d0be9cb74bfb
  question: |
    Are there any interesting commits between your VCC(s) and fix(es)?

    Write a brief (under 100 words) description of why you think this commit was
    interesting in light of the lessons learned from this vulnerability. Any
    emerging themes?

    If there are no interesting commits, demonstrate that you completed this section by explaining what happened between the VCCs and the fix.
curated_instructions: |
  If you are manually editing this file, then you are "curating" it. Set the
  entry below to "true" as soon as you start. This will enable additional
  integrity checks on this file to make sure you fill everything out properly.
  If you are a student, we cannot accept your work as finished unless curated is
  set to true.
upvotes_instructions: |
  For the first round, ignore this upvotes number.

  For the second round of reviewing, you will be giving a certain amount of
  upvotes to each vulnerability you see. Your peers will tell you how
  interesting they think this vulnerability is, and you'll add that to the
  upvotes score on your branch.
announced_instructions: |
  Was there a date that this vulnerability was announced to the world? You can
  find this in changelogs, blogs, bug reports, or perhaps the CVE date. A good
  source for this is Chrome's Stable Release Channel
  (https://chromereleases.googleblog.com/).
  Please enter your date in YYYY-MM-DD format.
fixes_vcc_instructions: |
  Please put the commit hash in "commit" below (see my example in
  CVE-2011-3092.yml). Fixes and VCCs follow the same format.
description_instructions: |
  You can get an initial description from the CVE entry on cve.mitre.org. These
  descriptions are a fine start, but they can be kind of jargony.

  Rewrite this description in your own words. Make it interesting and easy to
  read to anyone with some programming experience. We can always pull up the NVD
  description later to get more technical.

  Try to still be specific in your description, but remove Chromium-specific
  stuff. Remove references to versions, specific filenames, and other jargon
  that outsiders to Chromium would not understand. Technology like "regular
  expressions" is fine, and security phrases like "invalid write" are fine to
  keep too.