CVE-2016-1656

CVE: CVE-2016-1656
CWE:
- 284
- 23
bugs:
- 570750
repo: 
vccs:
- note: 'The commit did not include a sanitizer for the http content disposition (filename)

    '
  commit: 99aace34fc2b2ed5f2f62ca4dd61b6d81da9a13d
fixes:
- note: |
    The fix commit includes the code that parse the incoming file name in the
    http request to be sanitized before passing to the android download controller
  commit: 168f723d0f0ce60d92a6307c754181f6d8644583
bounty:
  date: '2016-04-13 14:48:00.000000000 -04:00'
  amount: 500.0
  references:
  - http://chromereleases.googleblog.com/2016/04/stable-channel-update_13.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: The download comes from a website could attack an Android device through
      the chrome download manager
    applies: true
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  defense_in_depth:
    note: 
    applies: 
  secure_by_default:
    note: The code could have put sanitizer for filename and http request content
      disposition since it comes from an external network.
    applies: true
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 1717783002
upvotes: 2
mistakes:
  answer: |
    The team did apply the filename sanitizer; however, it was not part of the
    http request content disposition sanitization. What we can learn from this
    is when working with a download manager, you have to make sure the manager
    sanitize the filename and the file path from the http content disposition.
    I would say this is part of requirement mistake because the download manager
    is a critical part of the browser task and people use the download manager
    daily makes the manager a security risk.
  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: '2016-04-18 06:59:05.140000000 -04:00'
subsystem:
  name: downloads
  answer: The code was in the Android Download Controller which handles the downloads.
  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: Dec-17-2015
  answer: |
    The person who discover the vulnerability was probably concerns about the
    path travseral on an Android device and he wants to check it. Based on the
    https://bugs.chromium.org/p/chromium/issues/detail?id=570750
    He posted a YouTube video shows that the file is being downloaded to a wrong
    directory because Chrome did not check the http content disposition.
  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: |
  The download manager did not check the file name to make sure that an attacker
  can't download a file to an unwanted directory outside of the Chrome folder for
  downloads. This vulnerability occurs when a user downloads a file from a website
  and the website change the file's name with a relative path cause Chrome to
  put the file in a wrong directory with the http request.
unit_tested:
  fix: true
  code: true
  answer: |
    Automated unit tests exist; however, the developer did not check the http
    content disposition to make sure there is no path traversal. The fix now
    includes sanitization to avoid the path, and the unit tests check that as
    well. The http content disposition is part of the file name in an http
    request and happens in the hardware level rather than the software level.
  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: The major event is fixed by removing the entire file containing the code
    as it is no longer need.
  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: The file containing the fixed vulnerability code was removed at this commit.
      The file is no longer needed as result of https://codereview.chromium.org/2014803002/
    commit: b23f5b2c9e52784a9d11a3058214d85cb5eed49d
  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.