CVE-2017-15707

aka Old Json-lib, Fresh DOS

CVE: CVE-2017-15707
CWE: 477
bugs:
- WW-4892
vccs:
- note: Moved Rest Plugin into trunk
  commit: 6229ad7a4726717bf594e9b4e4afa90e1e028829
- note: 
  commit: 
fixes:
- note: Use Jackson handler instead of default for JSON
  commit: 941374ecdb99ccc316f6b527b8df0f1cf2bb80c0
- note: Removes the dependency from the plugins
  commit: 26dc995866c70e9c82c60c602f9704407a98c9c3
bounty:
  amt: 
  url: 
  announced: 
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: |
      This somewhat applies as the the outdated library being used would accept
      a json payload that would result in a DOS attack.
    applies: true
  least_privilege:
    note: 
    applies: 
  native_wrappers:
    note: 
    applies: 
  defense_in_depth:
    note: 
    applies: 
  secure_by_default:
    note: 
    applies: 
  distrust_dependencies:
    note: |
      The bread and butter of this vulnerability. A library is likely to run out
      of support one day. It's important to monitor flaws in libraries that
      aren't getting updates
    applies: true
  environment_variables:
    note: 
    applies: 
  security_by_obscurity:
    note: 
    applies: 
  frameworks_are_optional:
    note: 
    applies: 
upvotes: 2
mistakes:
  answer: "The main mistake that was made was keeping around old, outdated libraries\nand
    still using them, despite them not receiving any security updates. The\nteam began
    using this library in 2007 and didn't stop using it until it was\ndiscovered that
    a user could cause a DOS attack.\n\nThe team seems to have taken the proper initiatve
    of replacing the old\nlibrary with a new one (Jackson), that is still being worked
    on and\nreceiving security updates. It did take some time for them to switch things\nover
    to using Jackson though as can be seen in some later commits showing\nthem switching
    to Jackson up to two months after the initial switch was\nmade. It was also noted
    that instead of fully removing the ability to use\nthe outdated json-lib library,
    they instead leave it as an optional thing,\nwith Jackson acting as the defualt
    JSON reader. They seem to be making proper\nsteps towards preventing the vulnerability,
    but still have some work to do,\nas there was no mention of removing json-lib
    as optional.\n\nThe team does have a good reason to keep json-lib though. There
    may be some \napplications that other teams have developed that use struts with
    json-lib.\n"
  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: 'Old Json-lib, Fresh DOS

  '
reported: '2017-11-17'
announced: '2017-10-21'
subsystem:
  name:
  - plugins
  - rest
  answer: |
    Looking through paths from the original commit that introduced the problem,
    it seems to be included in their rest plugins
  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: |
    Looking through Apache Struts' Jira website shows that they have recognized
    the problem and that they are addressing it, however there is no indication
    of the potential vulnerability associated with the deprecated library.
    Looking through the pull requests does not show anyone mentioning this.
  apache: 
  contest: false
  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 Apache
    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 "apache" 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: |
  Struts was using an outdated library in order to read and process JSON files.
  As a result, a special type of JSON file could be created that could cause a
  Denial of Service (DoS) attack. Since the library was outdated and no longer being supported, this
  problem would never be resolved.
unit_tested:
  fix: false
  code: true
  answer: |
    There are tests present that handle this vulnerability. At the time of the
    fix however, they were still based on the outdated library. There was a
    commit 3 months later that added tests to handle the new library.
  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".
future_fixes:
- note: 
  commit: 
curation_level: 0
previous_fixes:
- note: 
  commit: 
- note: 
  commit: 
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!)
security_bulletin: S2-054
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 commit deals with cleaning up remnants of strusts1 by removing
      deperecated plugins. This is interesting because this shows that they
      continually cleaned up deprecated plugins and libraies over time, yet
      still had json-lib, which had not been updated for some time at the time
      of this commit.
    commit: ffe0e20edd9d5386f4410fddd970286a69373243
  - 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 \nentry below to \"true\" as soon as you start. This will enable additional\nintegrity
  checks on this file to make sure you fill everything out properly.\nIf you are a
  student, we cannot accept your work as finished unless curated is\nset to true.\n"
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 SVN commit number in "commit" below, and any notes about how this
  was discovered in the "note" field.
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 Struts-specific
  stuff. Remove references to versions, specific filenames, and other jargon
  that outsiders to Struts 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 fixes for the same issue before and after
  this CVE below.