CVE-2013-2844

CVE: CVE-2013-2844
CWE:
- 416
- 399
bugs:
- 196393
repo: 
vccs:
- note: |
    The commit did not include an if statement to verify the pointer is
    still allocated and attempt to use the pointer regardless of allocation.
  commit: 9f6f5a8218bff29ab45b497e252302fe0a4f024f
fixes:
- note: |
    The fix commit fixes the use after free vulnerability to prevent the
    pointer with invalid address being used. The state.clear() function
    fixes the pointer.
  commit: d2ff3d144355df7d4b92feb91b9eeb61a741b5bf
bounty:
  date: '2013-05-21 12:30:00.000000000 -04:00'
  amount: 1000.0
  references:
  - http://chromereleases.googleblog.com/2013/05/stable-channel-release.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: 
    applies: 
  distrust_input:
    note: |
      Due to the ability of external networks to free the CSS renderer,
      the memory pointers may be freed and reused again outside of the control
      of the Chrome application. This vulnerability can lead to potential crashes
      or denial of service vulnerabilities.
    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:
- 14064008
upvotes: 4
mistakes:
  answer: I believe it was the coding mistake because the person did not think of
    checking the pointer to ensure it is not freed before using it. So, it is essential
    to think about all cases what the pointer will do during the process even if it
    becomes complex. When the code becomes complex, try to apply some practices such
    as check if the pointer is valid or not rather than figure out all cases for the
    pointer.
  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: '2013-05-22 09:29:56.067000000 -04:00'
subsystem:
  name: Blink
  answer: The mistake was in the CSS Renderer component. It did not impact outside
    of the subsystem.
  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: Mar-14-2013
  answer: The vulnerability is found through a test case by Sachin Shinde(@cons0ul)
  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: |
  Use after free vulnerability occurs when the CSS renderer attempts to use
  the same pointer after freed causes chrome to crash. An attacker can use
  style resolution as vulnerability access to cause an unspecific impact.
  This is done by placing a CSS file on the server and wait for a client to
  fall in the bait. As a consequence, memory might be accessed by something
  that is not supposed to happen or data on Chrome might be lost. Another cause
  to the vulnerability could be a denial of service to make Chrome unavailable.
unit_tested:
  fix: true
  code: true
  answer: The unit test is added to verify the pointer for the CSS renderer and check
    whether if the specific case cause Chrome to crash or throw an assertion.
  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: |
    There were no major events. During this time, the directory was changing several
    times to clean up names for refactoring.
  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: The vulnerability was straightforward to fix because the pointer has to
    clear the invalid address so the invalid address will not be called again by the
    function, state.clear().
  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.