CVE-2013-0841

CVE: CVE-2013-0841
CWE:
- 20
- 129
bugs:
- 169770
repo: 
vccs:
- note: |
    This VCC used the index in the array without checking to see if it was
    within bounds.
  commit: 9fb83e856fc12168151094df31e57177e4844417
- note: "This VCC created the function where the array and index was used, and \nalso
    did not check to see if it was within bounds.\n"
  commit: 55126134af52fe0f6a426f0f7ccfeeb8cf2c9f28
fixes:
- note: 'The fix was exiting the function if the index was out of bounds.

    '
  commit: 85f2fcc7b577362dd1def5895d60ea70d6e6b8d0
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: 
    applies: 
  distrust_input:
    note: |
      Array indexes should always be checked, especially if they result from outside
      variables.
    applies: true
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  defense_in_depth:
    note: |
      It can be assumed that the index for the type is already within the
      defined types, but it case it does not the index should be checked.
    applies: true
  secure_by_default:
    note: 
    applies: 
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 11880032
- 11885026
- 11875013
upvotes: 3
mistakes:
  answer: "This vulnerability was introduced during the implementation phase of development.\nI
    believe this vulnerability was the result of a coding mistake, but it could be\nthe
    result of a design mistake as well. Due to the relatively simple nature of\nthis
    vulnerability I believe that it could have simply been a mistake done by the\nprogrammer.
    Not properly checking array indexing is something can be easily\nforgotten. If
    input validation was not part of the design, then this is a design\nmistake as
    well. In order to prevent this vulnerability going forward, it must be \nremembered
    that array indexes should always be validated before use. The chromium\nshould
    also consider improving their unit testing plan. Array indexing is a\nvulnerability
    that can usually be caught during unit testing.\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: '2013-01-24 16:55:05.557000000 -05:00'
subsystem:
  name: browser
  answer: 'This was in the browser subsystem. This is because it is within the chrome
    directory.

    '
  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: '2013-01-14'
  answer: "This vulnerability was discovered by a user and reported to the development
    team.\nThe vulnerability could be shown when a patch put a multiplier on the index.
    Then\nif the user navigated to www.pandora.com, the browser crashed. This vulnerability\nis
    not specific to www.pandora.com, but www.pandora.com was able to create the \nright
    environment to envoke this crash.\n"
  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: "In the content-blocking funtionality of Google Chrome, there is a\nvulnerability
  where an array index is not checked. Content blocking\nis important to protect the
  user from unsafe scripts. \n\nThis vulnerability could potentially allow remote
  attackers to cause a denial\nof service (DoS). It could also cause the disclosure
  of information and\nunauthorized modification of data. This array is responsible
  for logging the\ntype of content settings accessed.\n\nThe fix for this vulnerability
  is to prevent the array index from going lower\nthan zero or higher than the size
  of the array.\n"
unit_tested:
  fix: false
  code: false
  answer: "There is no evidence of automated unit tests for this vulnerability. \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: "This vulnerability appeared when the team was moving content settings code
    out of the \ncontent module.\n"
  events:
  - date: '2011-5-13'
    name: The team is moving content settings out of the content module.
  - date: '2011-5-13'
    name: The team finishes moving content settings out of the content module
  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 was an interesting commit that made the the content settings not depend on an exact
    set of content types. This commit may explain how the vulnerability may have taken place.
    By deviating from a set number of types, it opened the array up to indexing errors.
  commits:
  - note: This commit made UI classes not depend on an exact set of content types.
    commit: 30c8864376a9cd251b7815b6795ed5db6988b1af
  - 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.