CVE-2016-1630

CVE: CVE-2016-1630
CWE:
- 264
- 346
bugs:
- 560011
repo: 
vccs:
- note: |
    This commit simply added the file in question to the repository. When the file
    entered the repo, it did not have any way of handling the issue that allows an
    attacker to access a secondary webpage by exploiting the improper widget updates.
  commit: 07fa7abcaf0cc4a2426bbbd18864a7772ffa3f96
fixes:
- note: |
    This patch adds a RAII guard that runs deferred widget updates
    at the end of parserRemoveChild. RAII, Resource Acquisition Is Initialization
    is commonly found in C++ when dealing with resource management and controlling
    mutex locks in multi-threaded applications. In short, this ensures the lifetime
    of an object is bound to the scope of a variable.
  commit: '05926d6f4e749cd49a16fa04a35e3498eb1b01a0'
- note: |
    parserRemoveChild: Avoid unintended DOM modifications after user script run.

    Surprisingly, ContainerNode::parserRemoveChild may run arbitrary user script
    during its DOM modification if its target contained iframes.

    Before this CL, this could lead to corrupt DOM tree, as the target node could
    be moved during parserRemoveChild execution.

    This CL adds a bail-out if stmt after disconnecting child frame to abort if precondition has changed.
  commit: 2c36e1fa592c341f27f758cf8b6770957c9bfdd4
bounty:
  date: '2016-03-02 15:41:00.000000000 -05:00'
  amount: 8000.0
  references:
  - http://chromereleases.googleblog.com/2016/03/stable-channel-update.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: 
    applies: false
  least_privilege:
    note: |
      This vulnerability poses a threat to the Principle of Least Privilege, as
      Same-Origin Policy aims to protect authentic sessions, the fact that an
      attacker could directly access a resulting webpage without the proper
      origin grants them privileges well beyond what they should have. The 2
      fixes act as layers to protect the DOM tree from unauthorized manipulation.
    applies: true
  native_wrappers:
    note: 
    applies: false
  defense_in_depth:
    note: 
    applies: false
  secure_by_default:
    note: 
    applies: false
  environment_variables:
    note: |
      Because an attacker is allowed access to a resulting (second) webpage, they
      could compromise a users browser environment variables such as cookies.
    applies: true
  security_by_obscurity:
    note: 
    applies: false
  frameworks_are_optional:
    note: 'This CVE was rooted in the use of Blink, a web framework.

      '
    applies: true
reviews:
- 1574913003
- 1464223002
upvotes: 3
mistakes:
  answer: |
    This vulnerability was a combination of coding and design mistakes. Widget
    updates were improperly handled, causing a delay that could facilitate the
    manipulation of the DOM tree. The solution was simply to implement a method
    that would effectively run the updates to prevent the acquisition of resources
    from an external actor. Multiple fixes combined when targeting the prevention
    of unauthorized DOM tree manipulation, as the initial fix did not account for
    the update issue with widgets.
  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: '2016-03-05 21:59:00.137000000 -05:00'
subsystem:
  name:
  - dom
  - parser
  answer: 'Dependent on file paths.

    '
  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: '2015-11-22'
  answer: |
    This vulnerability was discovered via an unprotected invocation of
    ContainerNode::removeBetween, as ContainerNode::parserRemoveChild was not
    within the scope of HTMLFrameOwnerElement::UpdateSuspendScope. This caused
    instances where a plugin node with an associated widget would be removed, yet
    updates fired during this process could corrupt the DOM tree.
  google: false
  contest: false
  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: |
  This refers to the ContainerNode::parserRemoveChild function in
  WebKit/Source/core/dom/ContainerNode.cpp in Blink, as used in Google Chrome
  before 49.0.2623.75, which mishandles Widget updates. Taken from Chromium's
  Developers page: 'At the root of a View hierarchy is a Widget, which is a
  native window. The native window receives messages from Windows, converts
  them into something the View hierarchy can understand, and then passes them
  to the RootView.'

  The mishandling of Widget updates results in an easier medium for remote
  hackers to bypass the Same-Origin Policy, allowing them access to data in
  a second web page.

  Normally, an origin webpage and a second/destination webpage must have the
  same combination of URI scheme, port number, and host name, if data in the
  second webpage is to be accessible by the origin webpage.
unit_tested:
  fix: true
  code: true
  answer: |
    Yes, the commits do show signs of unit testing. In some commits, new tests were
    added or implemented, and in other commits it was specified that no new tests
    were added or used. So, the unit testing varied by commit.
  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: 'Nothing to show.

    '
  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: 'See below.

    '
  commits:
  - note: |
      parserRemoveChild: Avoid unintended DOM modifications after user script run.
      Aims to prevent an attacker from gaining access to the DOM via Javascript execution
    commit: 2c36e1fa592c341f27f758cf8b6770957c9bfdd4
  - 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.