CVE-2015-1252

CVE: CVE-2015-1252
CWE:
- 119
- 787
bugs:
- 474029
repo: 
vccs:
- commit: 4ea9f181e9d73476f2c1bb235c533edb88dc6296
- note: The code was introduced as completely new files to provide functionality to
    be used in WebRTC logging and acts as a partially circular memory buffer wrapper.
    There is a bug associated with the commit (229829), but the link is locked behind
    a permissions wall. The found review number is 13473005 for the initial code submission.
fixes:
- note: The actual fix
  commit: ab42594ec3070953971f43b384f38f3c2b65d4ea
- note: The code fixer added themselves as an author
  commit: eb467f661aaa26642b8e9ec9834a8a8a56ccf985
bounty:
  date: '2015-05-19 11:49:00.000000000 -04:00'
  amount: 16337.0
  references:
  - http://chromereleases.googleblog.com/2015/05/stable-channel-update_19.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: The vulnerability here is that large inputs were not checked for
    applies: true
  distrust_input:
    note: 
    applies: 
  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:
- 1061053002
- 1117763002
- 1131943003
upvotes: 7
mistakes:
  answer: "The chosen CWE is 787 (Out-of-bounds Write) has no mitigation strategies\nlisted
    however there are mitigation strategies in CWE-119 (Improper \nRestriction of
    Operations within the Bounds of a Memory Buffer) which is\nwhat NVD lists as the
    class of the CVE issue. I have chosen CWE-787 as\nthat is the exact issue that
    occured but the NVD listed CWE-119 has what\nI would consider applicable, specifically
    the mitigations in the\nimplementation stage. The fix is specifically addressing
    the mitigation\nof checking the buffer boundaries if accessing the buffer in a
    loop\nto make sure you are not in danger of writing past the allocated space.\nSince
    the issue at its core is a lack of checking proper space checking\non the buffer
    size vs input size when handling the wrap around case, the\nfix moves the wrap
    around content out of the initial write loop to ensure\nsafety when writing the
    given input. The initial implementation simply did\nnot include thorough enough
    testing to catch this edge case.\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: '2015-05-20 06:59:04.370000000 -04:00'
subsystem:
  name: common
  answer: "Based on the description in the CVE along with identification from source
    file \ndirectory paths. From the VCC it was initially to be utilized by the WebRTC
    logging.\n"
  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: 
  answer: The bugs.chromium.org page is blocked by a permission wall. The issue was
    found by an anonymous user.
  google: 
  contest: Found by anonymous
  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: 
description: "The vulnerability was in Chromium's common utility functionality, specifically\na
  new implementation of a \"PartialCircularBuffer\" which was basically a buffer\nthat
  could wrap around *n number of times to have a continuous write of data.\n\nThe
  implementation, which was in C++, didn't handle the wrap around buffer write\ncase
  for large amounts of data properly. This had the possibiliy of resulting \nin data
  being written to memory that it was not intended for (an \"invalid write\"),\ncorruption
  of data, crashes or most significant to the security aspect of the\nissue allowing
  for arbitrary code execution as it was functionally a \"buffer \noverflow\" scenario.\n\nThe
  way that this could be exploited would be if an attacker found a way to \naccess
  the web logging that was being utilized and pushing any very large amount of\ndata
  to the target log write buffer which would result in a denial of service\nattack
  on the system. Since this particular issue was a common utility the potential\nattack
  possibilities while being more widespread would also depend on how the\n\"PartialCircularBuffer\"
  was being used in the different modules.\n"
unit_tested:
  fix: true
  code: true
  answer: They added a function to test memcpy with large input
  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: The code was moved from content/common/ to chrome/common for WebRTC logging
  events:
  - date: May 31, 2013
    name: 6ef98b5a0dabccfe9271697efee657316693cbee
  - 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: "There is no significantly interesting commits as the problem was a core
    problem\nwith the implementation of the wrap around scenario of the PartialCircularBuffer
    due to\nan out of bounds write that occured after the initial portion of the data
    was written to\nthe buffer. The only commits that occured between the VCC (initial
    implementation) and \nthe fix was one to add append support to the PartialCircularBuffer
    instead of just overwrite\ncapabilities. Originally this was of interest but after
    further investigation it was determined\nthat the problem was with the core implementation
    of the DoWrite and Write functionality and\nthe additional support for append
    did not affect it at all as it was simply using the same code\nwith an additional
    switch to determine whether or not to clear the buffer prior to attempting a\nwrite.
    This append support was to be used in logging machine info to diagnostic the WebRTC
    log.\nThe only other commit that occured was moving the file from content/common
    to chrome/common and\nchanging the copyright info.\n"
  commits:
  - note: 
    commit: 
  - 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.