CVE-2015-1237

CVE: CVE-2015-1237
CWE:
- 416
bugs:
- 461191
repo: https://chromium.googlesource.com/chromium/src/
vccs:
- note: "The VCCS did not introduce a significant number of SLOCs in the commit. This\ncommit
    contains the first instance of freeing a pointer, without zeroing the \npointer.
    The is likely due to engineering oversight over the future uses of \nthe troubled
    pointer. \n"
  commit: cbf8849f3e446c86e29cc176d3214529d12a7a61
fixes:
- note: "The fix for this vulnerability only required limited rework; to avoid a \nuse-after-free,
    the pointer should be zeroed after deallocation. That is\nexactly what the author
    did to resolve this vulnerability. The troubled \npointer was set to nullptr,
    once its destructor was called. Additionaly, \nthe engineer added a check to prevent
    proccessing that utilizes the pointer\nthat was just freed.\n"
  commit: cfaa4468f3394995a9f1565104ee2743a30d58e0
bounty:
  date: '2015-04-14 13:41:00.000000000 -04:00'
  amount: 3000.0
  references:
  - http://chromereleases.googleblog.com/2015/04/stable-channel-update_14.html
lessons:
  yagni:
    note: 
    applies: false
  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: false
  complex_inputs:
    note: 
    applies: false
  distrust_input:
    note: "This vulnerability is caused by manipulating input vectors to trigger IPC\nmessage
      during the detaching operation. Therefore, the IPC messages cannot \nbe trusted
      to be used in a manner consistent with the design of Google Chrome. \n"
    applies: true
  least_privilege:
    note: "The render process is sandboxed. Therefore, if an attacker was able to
      \nexploit this use-after-free to execute arbitrary code, the privileges \nthey
      would enjoy is only the ones that the render process was assigned.  \n"
    applies: true
  native_wrappers:
    note: 
    applies: false
  defense_in_depth:
    note: 
    applies: false
  secure_by_default:
    note: 
    applies: false
  environment_variables:
    note: 
    applies: false
  security_by_obscurity:
    note: 
    applies: false
  frameworks_are_optional:
    note: 
    applies: false
reviews:
- 1002493004
- 1007123003
- 1021313002
upvotes: 
mistakes:
  answer: "This vulnerability is resultant of a coding mistake. This vulnerability
    \nonly required a two SLOC change, which is indicative that this vulnerability
    \nwas sourced from an oversight of the author. The fix only required following
    \nthe MITRE recommended mitigation, which is to set the pointer to null after
    \nfreeing. \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: '2015-04-19 06:59:02.477000000 -04:00'
subsystem:
  name: renderer
  answer: "The mistake was done in the class which handles the frame rendering for
    \nGoogle Chrome. More specifically, when the frame was being detached and the
    \nframe was being freed.  \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: '2015-02-25'
  answer: |
    This vulnerability was discovered through Google’s bug bounty program.
    The submitter did not supply bountiful information about the discovery
    of the bug apart from a video to reproduce the error.
  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: "Google Chrome was susceptible to a use-after-free vulnerability, where
  a \npointer is used after it has been freed. Accessing a pointer after it has been\nfreed
  can cause unintended behavior like: program crash, unexpected runtime \nvalues,
  and change in program execution. An attacker could exploit the \nvulnerability,
  through a specially crafted website, cause renderer crashes or \narbitrary code
  executions.. \n"
unit_tested:
  fix: true
  code: true
  answer: "The engineer implemented a unit test that sends a new message to the frame\nafter
    it has been freed. This unit tests the condition where this \nvulnerability could
    be exploited. \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: "It is evident that during the timeline of this vulnerability, there was
    \nsignificant development within this subsystem of Google Chrome. \n"
  events:
  - date: '2014-07-16'
    name: "Google Chrome Version 36.0.1985, adds DirectWrite support for font \nrendering.\n"
  - 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: "Between the VCC and the fix, there was significant rework in the detach
    \nroutine, which freed the frame object. It is likely that the high turnover\nof
    this function contributed to the free-after-use.\n"
  commits:
  - note: "This commit introduced a new function for detaching prior to the object
      \nfree.\n"
    commit: 3d35caa233020f4067d50051565467efd53986fb
  - note: "This commit introduced a additionaly function for detaching prior to \nthe
      object free.\n"
    commit: 1dbe123c5e7b2d41e517049c1b98d8ad75563b98
  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.