CVE-2014-7934

CVE: CVE-2014-7934
CWE:
- 416
bugs:
- 427249
repo: 
vccs:
- note: "\"Original if statement was created by Apple before WebKit was \nforked by
    Google\"\n"
  commit: 56d3dae3e51988ba04982b46b31eae658bcdb784
fixes:
- note: ''
  commit: 73c390dbc4a5f379f41f2b51b697afaab2118767
- note: ''
  commit: 2e5f9bb3de559fa7ace48d3202ce24651d4a3e73
- note: ''
  commit: 73c390dbc4a5f379f41f2b51b697afaab2118767
- note: ''
  commit: abbb4880590d4b4934d0a2db3251f253733ae362
bounty:
  date: '2015-01-21 15:11:00.000000000 -05:00'
  amount: 2000.0
  references:
  - http://chromereleases.googleblog.com/2015/01/stable-update.html
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: "This vulnerability is not something the normal user would encounter. The
      person who \ndiscovered this vulnerability had to execute a very complex layer
      of XML, which is \na tree-based structure, to cause this memory issue.\n"
    applies: true
  distrust_input:
    note: 
    applies: 
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  defense_in_depth:
    note: 
    applies: 
  secure_by_default:
    note: "This vulnerability appeared to be an edge case caused under certain circumstances.
      \nThe original developers must have assumed that the Object was no longer \naccessed
      after deletion. \n"
    applies: true
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 730513002
- 745613003
- 751593002
- 721103002
- 718293002
- 722093002
upvotes: 17
mistakes:
  answer: "This vulnerability was simply a rare abuse case that broke an assertion
    in the style \nrendering of WebKit. This vulnerability appears to have been present
    as far back as \nwhen Google forked the WebKit repository from Apple. When blamed,
    the original code's \nlast author was an Apple engineer, at least 5 years before
    this bug was identified.\n\nThere was not much in terms of design or coding mistakes
    that were made. This vulnerability \nwas an extreme edge case, however, the Google
    engineers appeared to have some issues finding \nthe correct patch for this. Some
    commits were made, but were then later reverted because \nthey either did not
    fully solve the problem, or they broke more features.\n"
  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: '2015-01-22 17:59:15.600000000 -05:00'
subsystem:
  name:
  - webkit
  - blink
  answer: Based on Bug Report and file locations
  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: '2014-10-26'
  answer: An external user disocvered this bug and reported it to Google
  google: false
  contest: true
  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: false
description: "A user was able to crash Chrome by executing a complex series of JavaScript
  \ncommands. This crash was caused by a used-after-free issue. By accessing memory
  \nno longer available, the program crashed and generated a sensitive crash dump.
  \ \n"
unit_tested:
  fix: true
  code: false
  answer: "No unit tests appear to be present before the fixes. Unit tests \nwere
    added later.\n"
  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: 'This CVE/bug originates to the original WebKit fork from Apple.

    '
  events:
  - date: '2010-11-10'
    name: WebKit is forked from Apple to Google
  - 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: "This commit was not only reported twice, but it was also reverted soon
      \nafter being merged. Code was reverted due to the fix not being completely
      \nsuitable and was pulled until a more appropriate fix could be made.\n"
    commit: 73c390dbc4a5f379f41f2b51b697afaab2118767
  - note: 
    commit: 
  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.