CVE-2016-3092

aka FileUpload tiny buffer

CVE: CVE-2016-3092
CWE: 20
bugs:
- 91453
vccs:
- note: SVN rev 412780, from Tomcat website.
  commit: f1911d8c5f0dc3774fe731ae27d4a9a9b39197c3
- note: 
  commit: 
fixes:
- note: |
    Prevents the user from making a boundary string that is just shorter than the
    buffer.
  commit: 8e67e4a4799a9765b3bd777eed3ee17f00514441
- note: 'Prevents the user from making a boundary string that is too long.

    '
  commit: 29384723d8d9645b87e05be9fa369a4deeb78b9c
bounty:
  amt: 
  url: 
  announced: 
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: |
      I would say this follows the same as what I wrote in distrust_input. Especially since a larger and complex file could
      make the multipart boundry smaller than the buffer.
    applies: true
  distrust_input:
    note: |
      By setting the buffer size to the boundary string times two, you are
      distrusting the input to ensure that a long boundary string won't cause a denial
      of service attack.
    applies: true
  least_privilege:
    note: 
    applies: false
  native_wrappers:
    note: 
    applies: false
  defense_in_depth:
    note: 
    applies: false
  secure_by_default:
    note: 
    applies: false
  environment_variables:
    note: 
    applies: false
  security_by_obscurity:
    note: 
    applies: false
  frameworks_are_optional:
    note: 
    applies: false
upvotes: 5
mistakes:
  answer: |
    I think this was a coding mistake because, when getting string input, it is good
    practice to check the length of the string to make sure that it won't cause any
    problems. I think the fix looks proper because it sets the buffer size to the
    boundary length times two if the boundary string is too large. This helps to prevent
    the DoS vulnerability. I think that another good fix would have been to not
    directly append prefixes.
  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 in the software
    engineering industry would find interesting.
nickname: FileUpload tiny buffer
reported: '2016-05-09'
announced: '2016-07-04'
subsystem:
  name: 
  answer: fileupload
  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: '2016-05-09'
  answer: Found by TERASOLUNA Framework Development Team at the Software Engineering,
    Research and Development Headquarter.
  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
    * If it's clear that the vulnerability was discovered by a contest,
      fill in the name there.
    * The "automated" 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", BUT please write down
    where you looked in "answer".
  automated: 
description: Tomcat uses a package that is a copy of Apache Commons FileUpload but
  renmamed. This would follow the requirements of the Servlet specification. A vulnerability
  was identified in this when the length of the multipart boundary was below the size
  of the buffer of 4096 bytes that it used to read the uploaded file. (The file is
  much bigger than expected) The error was the upload process would take several orders
  much larger than if it was the normal 10 bytes long. This is a denial of service
  vulnerability.
unit_tested:
  fix: false
  code: false
  answer: "It doesn't appear that the code was unit tested before or after the fix.
    No unit tests for the file uploaded was not \nchanged or found\n"
  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?
    Write the reasoning behind your answer in the "answer" field.
    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. Must be just "true" or "false".
    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.
    Must be just "true" or "false".
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!)
incomplete_fixes:
- note: 
  commit: 
- note: 
  commit: 
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: "No it appears the code was fixed and the issue didn't resurface again.
    However they did have to wait \ntill the next release to patch the vulnerability.\n"
  commits:
  - note: |
      This commit was interesting because it made some major changes to how the
      boundary prefix was appended to the beginning of the boundary when the arraycopy
      method was used, but it still didn't check the length of the boundary to ensure
      it wasn't too long.
    commit: bcefe58374c421c9431c144938e2e91d22f5061b
  - note: |
      This commit was interesting because it mitigated another DoS vulnerability
      involving a boundary string.
    commit: 29384723d8d9645b87e05be9fa369a4deeb78b9c
  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: |
  Students: when initially writing this, ignore this upvotes number.
  Once this work is being reviewed, 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.
nickname_instructions: |
  Nickname is optional. Provide a useful, professional, and catchy nickname for
  this vulnerability. Ideally fewer than 30 characters. This will be shown
  alongside its CVE to make it more easily distinguished from the rest.
reported_instructions: |
  Was there a date that this vulnerability was reported to the team? You can
  find this in changelogs, blogs, bug reports, or perhaps the CVE data.
  Please enter your date in YYYY-MM-DD format.
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 data.
  Please enter your date in YYYY-MM-DD format.
fixes_vcc_instructions: |
  Please put the Git commit SHA in "commit" below, and any notes about how this
  was discovered in the "note" field.
  Refer to our instructions on how to find a Git SHA from an SVN revision.
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.
incomplete_fix_instructions: |
  Did the above "fixes" actually fix the vulnerability?
  Please list any fix commits for this vulnerability that had to be corrected
  at a later date.