angler-fishThe Vulnerability History Project

CVE-2011-3096

There was a vulnerability on Linux machines that would allow remote hackers to cause a denial of service attack through use-after-free of a particular error in the GTK implementation of the omnibox, a web browser address bar that also acts as a search engine. GTK is a toolkit used for creating graphical user interfaces.


After sifting through all of the commits and posts about the vulnerability, I would have to say that this mistake came from a misunderstanding of how GTK handles object removal. Unfortunately, the programmer was under the impression that GTK would handle closing the signal listeners for them. Because of this misunderstanding of a third party dependency, the vulnerability slipped into the code. I would have expected there to be a test to see if you could still call the signals even after destroying the object, but there was no such tests.
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CVE: CVE-2011-3096
CWE:
- 416
- 399
bugs:
- 123530
repo: 
vccs:
- note: |
    The file was moved from a different directory and the file history
    does not go back far enough to show when the issue first started
  commit: b30fc4641f66a903869ff5aa894f9622419234a7
fixes:
- note: Stopped listening to the signals before destroying the connection
  commit: 9fe90fe465e046a219411b192d8b08086faae39c
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: 
    applies: 
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  defense_in_depth:
    note: 
    applies: 
  secure_by_default:
    note: |
      I believe that this vulnerability could serve as an example of secure by
      default. The reason is that the engineer was under the impression that the
      dependency being used had taken care of the security issues surrounding
      use after free.
    applies: true
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 23257002
- 10269005
- 10103012
upvotes: 2
mistakes:
  answer: |
    After sifting through all of the commits and posts about the vulnerability,
    I would have to say that this mistake came from a misunderstanding of how
    GTK handles object removal. Unfortunately, the programmer was under the
    impression that GTK would handle closing the signal listeners for them.
    Because of this misunderstanding of a third party dependency, the
    vulnerability slipped into the code. I would have expected there to be a
    test to see if you could still call the signals even after destroying the
    object, but there was no such tests.
  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: '2012-05-15 20:55:03.027000000 -04:00'
subsystem:
  name: omnibox
  answer: |
    The vulnerability was part of the chrome browser subsystem. Inside of that,
    it was part of the GTK omnibox subsytem for the UI. This specific file was
    used for the popup view of the omnibox.
  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: '2012-04-15'
  answer: |
    The vulnerability was discovered by someone outside of the chromium
    organization. Using Ubuntu 10.10, the user tried appending data into the
    address bar, which caused the browser to freeze and crash. Credit for
    finding the bug was given to Arthur Gerkis.
  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: |
  There was a vulnerability on Linux machines that would allow remote hackers to
  cause a denial of service attack through use-after-free of a particular error
  in the GTK implementation of the omnibox, a web browser address bar that also
  acts as a search engine. GTK is a toolkit used for creating graphical user
  interfaces.
unit_tested:
  fix: false
  code: true
  answer: |
    There were no automated unit tests involved with this vulnerability. There
    were several tests that dealt with other functionality of the file that the
    vulnerability came from, but none that specifically tested communicating
    with the object once the connections were closed. There were unit tests
    involved with testing parts of the module, however there were no tests being
    performed for trying to communicate with the GTK popup after it had been
    closed.
  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: None
  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: 
  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.

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