CVE-2014-3157

CVE: CVE-2014-3157
CWE:
- 122
- 119
bugs:
- 368980
repo: 
vccs:
- note: Introduced the buffer was created and given by chrome instead of ffmpeg
  commit: 13f1e6af5ceb92cec9642f1deae8de7ae7904805
fixes:
- note: Changed buffer size calculation to match that of ffmpeg's default
  commit: 96e8ffb4e805c7266a2fc1fbe0e470052019bad9
bounty:
  date: 
  amount: 
  references: []
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 dealt with decoding video files, which are complex
      files that need to be handled correctly
    applies: true
  distrust_input:
    note: |
      This vulnerability could be exploited by a malicious embedded video,
      therefore, inputs from webpages should be distrusted
    applies: true
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  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:
- 308733002
- 270193002
upvotes: 2
mistakes:
  answer: "The coding error was a buffer overflow, caused by not allocating enough
    \nspace for ffmpeg to use for decoding. This mistake was because the buffer\nprovided
    by chrome did not use the same calculations for allocating space\nas a buffer
    that would be provided by ffmpeg.\n\nThis vulnerability was caused by misunderstanding
    how ffmpeg allocates and\nhandles video buffers. The team changed the code so
    Chorme provides a\nbuffer for ffmpeg to use instead of letting ffmpeg allocate
    a buffer, but\nthey used a slightly different calculation to determine the size
    of the\nbuffer. \n\nThe solution implemented was to allocate the same ammount
    of space as\nffpeg would have for the buffer, ensuring that there was enough room
    to \nnot overflow the buffer.\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: '2014-06-11 06:57:18.610000000 -04:00'
subsystem:
  name: media
  answer: Based on the description in CVE and the fix commit
  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: '2014-05-01'
  answer: "Found using ClusterFuzz (Inferno_flicker), then questionably reported as
    fixed \nby the same fuzzer. Engineers were unable to reproduce the issue using
    ffmpeg\nseperately so the search was narrowed until they found the buffer allocation\nthat
    caused the issue. They then fixed the vulnerability by replicating how \nffmpeg
    allocates the buffer.\n"
  google: true
  contest: 
  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: "When decoding a video, a buffer is allocated for each frame to be decoded
  in\nto. However, if the buffer is not large enough to hold the decoded frame, a\nheap
  overflow occurs, which can allow data to be written where it should not.\n\nThis
  Heap-based buffer overflow inside the function to get a video buffer for \ndecoding
  allows remote attackers to cause a denial of service by causing the\nsystem to crash.
  An exploited to abuse this could be a malicious video file\nembedded on a web page.\n"
unit_tested:
  fix: true
  code: true
  answer: |
    Looking at the fix commit, there were test cases for the code, but a new
    case was created to test the specific 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: No major events found during this time that I saw.
  events:
  - date: 
    name: 
  - 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 adds verification to the video size before allocating the
      frame, and changed only 2 lines of code. This may have prevented some
      cases of the vulnerability being used, but not all cases.
    commit: de90333e4f90bc8f35b74b0cc1433afd434eb93a
  - 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.