CVE-2015-1271

CVE: CVE-2015-1271
CWE:
- 122
- 119
bugs:
- 446032
repo: 
vccs:
- note: update from this commit was the final piece to reveal this vulnerability.
    There were other issues in the past that also contribute to this but the error
    of bad cast began that caused attention to this issue occured when this update
    was commited.
  commit: 962a1419cc1ed75c220a7e66cc69a8d7fcc33702
fixes:
- note: Added an alloc function to check for the cases where too much memory is going
    to be allocated for a PDF
  commit: bc1bb9d28de48fe3dd339ed1948bbba9addc4bd9
bounty:
  date: '2015-07-21 14:00:00.000000000 -04:00'
  amount: 3000.0
  references:
  - http://chromereleases.googleblog.com/2015/07/stable-channel-update_21.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: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
reviews:
- 868533003
- 1226403008
upvotes: 
mistakes:
  answer: The main factors that lead to the vulnerability were miscommunication and
    coding mistakes. I think it is clear looking through the comments that there was
    no clear task force on solving this error and many notes were inserted on the
    progress. This was clear by the mutliple comments back and forth on the Issue,
    trying to solve the bug.  Multiple months after the Issue was discovered and a
    solution was solved people agreed the orginal idea in the first comment would
    work.  The devloper on this had to be commented on to fix it, causing the bug
    to be open for months.  It had also exceeded the 60-day deadline for fixing a
    high severity security vulnerability that Google developers follow for Chromium.  There
    was also just a coding mistake in not checking for the alloc first.
  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: '2015-07-22 20:59:01.117000000 -04:00'
subsystem:
  name: PDFium
  answer: specific types of crafted PDF documents loaded through PDFium
  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: '2015-01-04'
  answer: This vulnerability was discovered after there was a merge to M44 and there
    were a few cases were the continuation in face of OOM was still possibly needed.
    This was difficult error to reproduce because of OOM. To work with this bug, a
    custom ASAN patch was created to limit the overal malloced size.
  google: true
  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: true
description: 'PDFium''s out of memory conditions are not properly handled. This allows
  remote attackers to cause a denial of service or other potential attacks from a
  heap-based buffer overflow. This results in heap buffer overflow from a large memory
  allocation of a crafted PDF document.

  '
unit_tested:
  fix: true
  code: true
  answer: 'Yes there were tests involved with this vulnerability, but the original
    set suit did not look for this specific case of a corrupted type of PDF.  Once
    the code was fixed, the tests were added along with them. The new automated test
    the new function FX_TryAlloc(). Tests about of the function removed FX_TryAllocNL()
    were removed along with the function, since it would suggest no limit, which could
    cause large memory allocations.

    '
  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: 
  events:
  - date: '2015-01-27'
    name: There was a comment on how the bug was not solved yet and nothing was being
      updated.
  - date: '2015-02-11'
    name: There was a comment on how the bug was not solved yet and nothing was being
      updated.
  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: 0
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.