CVE-2016-1647

CVE: CVE-2016-1647
CWE:
- 416
bugs:
- 590284
repo: 
vccs:
- note: Doesn't check the condition if navigation within page
  commit: 61ac9e2412b2915150f89d5b5bfafcf2e143af52
fixes:
- note: ''
  commit: e5787005a9004d7be289cc649c6ae4f3051996cd
- note: ''
  commit: 8be1ff11dc1fae61146dbcfaa38e12314d290dca
bounty:
  amt: 10500.0
  announced: '2016-03-24'
  references: http://chromereleases.googleblog.com/2016/03/stable-channel-update_24.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: 
    applies: 
  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: |
      The vulnerability was largely about how the browser decides, if the user
      is trying to navigate from inside a widget page. In normal circumstances
      the fullscreen widget screen will be deleted. But advantages can be taken
      by navigating or rendering pages from inside the widget window.
    applies: true
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 1811783002
- 1784673002
- 1747183002
- 1738233002
upvotes: 6
mistakes:
  answer: |
    The mistakes that led to this vulnerability were coding and design mistakes. When a fullscreen
    widget is created, a WebContentsImpl stores its routing id in fullscreen_widget_routing_id_.
    WCI assumes that this widget belongs to the process of the current main frame:
    GetRenderManager()->current_host()->GetProcess(), which it normally does. A compromised
    renderer can swap the process of the main frame, while keeping the fullscreen widget alive.
    Normally, the fullscreen widget would be deleted as the renderer navigates, but there
    is an exception. If the navigation was within the page, then the fullscreen is kept alive.
    This happens for example when only the url fragment changes.  In such case, renderer sets
    FrameHostMsg_DidCommitProvisionalLoad_Params::was_within_same_page = true and the
    browser mostly trusts that, even if the the navigation wasn't within page and the
    process was swapped. If the renderer swaps the process and sets was_within_same_page = true,
    the fullscreen_widget_routing_id_ will end up pointing to a wrong widget in the new process.
    If the renderer now closes fullscreen, this wrong widget is deleted. It is deleted manually
    in RenderWidgetHostImpl::Destroy(), because fullscreen widgets aren't owned by a smart pointer.
    Normal widgets are owned by a scoped_ptr render_widget_host_ in RenderViewHostImpl though.
    If such a widget is manually deleted by an attacker, the scoped_ptr in RVHI ends up holding a
    dangling 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: '2016-03-29'
subsystem:
  name: browser
  answer: Based on the description in the CVE and blog post.
  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: 
  answer: 'No evidence found

    '
  google: 
  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: 
description: |
  The navigation implementation in Google Chrome causes use-after-free vulnerability
  and allows remote attackers to cause denial of service, the bug allows
  unauthorized disclosure of information, allows unauthorized modification
  and allows disruption of service.
unit_tested:
  fix: true
  code: true
  answer: |
    From looking at the fix code it's clear that code was tested and they added
    a new test for fixing this vulnerability.
  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: I did not see any major events during this time.
  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: |
      No interesting commits, the vulnerability came to light when the function
      was first implemented.
    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.