CVE-2015-1299

CVE: CVE-2015-1299
CWE:
- 416
bugs:
- 416362
repo: 
vccs:
- note: Potential VCC. Introduced a function that stores a variable and returns the
    80-bit interger. This is the leading idea of what caused the UAF (use after free).
  commit: 30d3cc797b88fe2a8d68d959d7fb5ff3aae6beae
fixes:
- note: The owner was skyostil@chromium.org. The last commit. Removed the shared timer
    heap structure because it proved to be unreliable. Replaced with web scheduler.
  commit: 2a7c6d5616049eb1d10c3397ca33b936d220569c
- note: This was a revert to fix a potential issue. Also the VCC for the issue in
    ThreadTimers. This is where the file was introduced.
  commit: 46c4b2cc00daaafff42f7764289a79fb1476cdca
- note: Implement the new timers again with delayed tasks. This work will be reverted
    by next commit
  commit: 46ce7271f51a66d86c301c7f261fec438f1a23ca
- note: Revert Caused by a leak in another portion of code.
  commit: 753b7c8e21397bb370ae5b46af73287211d6f6b8
- note: Similar to 438f1a23ca
  commit: e313fd2e8596bafa6cb384855bd4f6747251bf5f
- note: Revert of timers, back to heap.
  commit: 29adc3195332e03d7c78a0c796300862e2e8aa74
- note: Implement timers again.
  commit: 0a9ae3e2bdf75e4ae7daf6e90d74cce26c355372
- note: Revert of Timers
  commit: a0cd100e9720be2f1863ffec813cca100fd2d247
- note: Implement Timers. The original fixing commit before all the reverts.
  commit: 76a4aa213cf20e49fd45ad77c64fe9ac458727f9
bounty:
  date: '2015-09-01 15:15:00.000000000 -04:00'
  amount: 2000.0
  references:
  - http://chromereleases.googleblog.com/2015/09/stable-channel-update.html
  - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1299
  - https://bugs.chromium.org/p/chromium/issues/detail?id=416362
lessons:
  yagni:
    note: There was a problem about making a complex heap structure when it did not
      need it. (So it was removed)
    applies: true
  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: Seeing the heap as a framework reveals that this could apply as removing
      it shows that using a heap was optional and it was not the best setup as it
      could be curropted
    applies: true
reviews:
- 1162753003
- 1134523002
- 1167023002
- 1151633004
- 1153763005
- 956333002
- 609483002
- 1162903005
- 959263002
upvotes: 4
mistakes:
  answer: |
    The vulnerability was a complex issue that never really led to a defined solution. It
    started with the fact they made the decision to create a heap and use that for a scheduler.
    This is an issue because it was not needed and added a good amount of complexity which makes
    security more difficult. In addition, it was in a relatively unpopular area with only a few people
    being familiar with the section. This allowed for the bug to exist for quite sometime after it was first found.
    The next issue was the fact there were no unit tests until AFTER the solution was found. This allowed
    for plenty of findable mistakes to pass through (as many as three). Lastly the way they came about a solution
    was very problematic. It looked like from the git history they did not properly test their solution in the
    system. as a whole. so it led to four reverts. This could stem from the fact that instead of investigating
    for the specific solution, they just wiped the entire subsystem.
  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: '2015-09-03 18:59:09.967000000 -04:00'
subsystem:
  name: blink
  answer: The mistake was found in the Blink Subsystem (currently within WebKit).
  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: '2014-09-22'
  answer: This was discovered by someone who had crashed a tab and went to another
    site and had it report a crash (when it should not have). They reported it in
    the Chromium bugs forum.
  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 an issue with timers being removed and the reference to the timer being used.
  Timers were set up so that they lived in a heap. The problem with this is there
  was logic that ended up freeing/removing a timer, due to a bad conditional. This conditional
  attempted to compare an 80-bit integer with a 64-bit integer. This would cause
  the program to update the heap and make a duplicate timer. Eventually, the timer would
  be deleted but the 'duplicate' (which is a pointer to the original) would be used.

  The fix was a complete overhaul of the timer file. Remove all references of a heap
  to use a more reliable scheduler.
unit_tested:
  fix: true
  code: false
  answer: Unfortunately, unit tests were not involved in finding this vulnerability.
    Furthermore, there are good signs to suggest there were not unit tests present
    before the fix. This is because the file of unit tests did not exist as of the
    time before the fix. Fortunately, the fix did have some unit tests added in within
    commit 645556929e1aad3f51f70d47a449998f4f7f1913 that added TimerTests.cpp.
  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: |
    When the issue was captured, there was not too many people working on the project.
    That means the issue took a long time to complete.
  events:
  - date: May 21, 2015
    name: Rework of subsystem(blink timer)/fix the bug
  - 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: 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: This initial commit of the unit tests that were created to test removing
      the heap.
    commit: 645556929e1aad3f51f70d47a449998f4f7f1913
  - note: Reverts of the solution occurred 4 times.
    commit: a0cd100e9720be2f1863ffec813cca100fd2d247
  - note: Implementation was implemented 5 times due to reverts.
    commit: 76a4aa213cf20e49fd45ad77c64fe9ac458727f9
  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. Files to look for timer.cpp and
  ThreadTimers.cpp
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.