CVE-2016-1639

CVE: CVE-2016-1639
CWE: 
bugs:
- 572224
repo: 
vccs:
- note: 
  commit: 
fixes:
- note: ''
  commit: c4e893a3352c34e1a22ec6afad115887a69f576e
bounty:
  date: '2016-03-02 15:41:00.000000000 -05:00'
  amount: 1000.0
  references:
  - http://chromereleases.googleblog.com/2016/03/stable-channel-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: "It is neccessary to check if the pointer to a memory is still available.
      \nThis vulnerability happened because the developer didn't check the situation
      where an old memory was freed and the system resued that memory. \n"
    applies: true
  distrust_input:
    note: 
    applies: 
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  defense_in_depth:
    note: "The fix for this vulnerability involved checking the null pointer for resource
      context.\nThe system store Storage instead of resource context pointer to access
      Device salt ID to avoid the case where the system free resource context. \n"
    applies: true
  secure_by_default:
    note: 
    applies: 
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 1692913003
- 1703733002
upvotes: 
mistakes:
  answer: "The Use after Free is a simple oversight issue when the system has to deal
    with pointer. However, it seem like the vulnerability is ignore in commit \nf9583f83523a0ad7c2c97300dfe303066bcb1ec0.
    The system attempted to retrieval the media device ID salt even after resourceContext
    is no longer available. \nThe design may not work well to lead to this vulnerability.
    It is important to have a solid design of how to handle memory allocation and
    free it afterward. "
  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: '2016-03-05 21:59:10.163000000 -05:00'
subsystem:
  name: webrtc_audio_private
  answer: The vulnerability was discovered in the webrtc_audio_private_api function
    . The subsystem is in the chrom bwoser api.
  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: '2015-12-25'
  answer: |
    An anonymous user replicated an error when he opened gmail. There is unknown error for the function CalculateHMACImpl
    and it cause a crash in the program when the user used a new incognito window .
  google: false
  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: false
description: "Based on the report of CVE-2016-1639, there is a Use after Free vulnerability
  in the WebRTC Audio Private API implementation in Google Chrome.\n\nUse after Free
  is a memory problem where the memory is referenced after it is freed. Developers
  usually face this problem in many application where\nthey have to allocate memory
  and the previoused memory was freeed. It may cause the program to crash or use unexpected
  value to perform a certain action. \n\nThe Use after Free vulnerability is dicovered
  in the file webrtc_audio_private_api.cc with the path browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.cc\nin
  the WebRTC API. The vulnerability may cause denial of service or unexpect result
  by dependent on resource context pointer. \n"
unit_tested:
  fix: false
  code: false
  answer: "There is no unit test involved in this velnerability. \nThere was no unit
    test for the function CalculateHMACImpl in this case.\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: commit 7b6559a8ce5327ab6a276accda2ad1c252926af7 show a change in audio output
    device for the api
  events:
  - date: '2016-02-03'
    name: The authoer Use TaskRunner instead of WorkerTaskRunner for audio output
      device enumerations in WebRTC audio private API.
  - 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: 0
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: "The lines between 209 - 213 provide a storage for resource context to access
      Storage Device salt ID later. \nThere is no code to check if this pointer still
      existed before the user can access Storage Device Salt ID. \n"
    commit: 6b490c6fd81af60c1e5962054205c417f1bb27e7
  - note: Deprecate methods were removed after a year. It is a long time to make this
      change.
    commit: 076ebedaa781461c668ea435ef3af3ca707775d5
  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.