CVE-2016-4438

CVE: CVE-2016-4438
CWE: CWE-20
bugs: []
vccs:
- note: Disable eval expressions
  commit: 7e6f641ebb142663cbd1653dc49bed725edf7f56
- note: WW-4162 Doesn't check for disallowed ognl expressions if getting from…
  commit: afae14eb86d24d3b6f8dd1d1a23da2b355c5a0d7
- note: WW-4146 Caches only valid Ognl expressions to avoid cache attack
  commit: 86813c1a7214bc002a5d7ce9981a9ef333e27142
- note: Move XWork core under Struts 2 to simplify relese proces
  commit: 0c543aef318341ca9bd482e15f1637497b8a4dfd
fixes:
- note: Added missing blocked classes. Struts 2.3.29
  commit: 46517afb1402fbf3fd84089920b43cc07e948a92
- note: Blocks chained expressions
  commit: 5190b53673a710ead31bbb5f82cf4ca171994629
- note: Upgrades OGNL
  commit: d36f31b3e1a65c619b1cbaf743baa3efc66168be
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: 
    applies: false
  distrust_input:
    note: A user can input malicious input and execute aribtuary code.
    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: "This is an input validation error. It is an input validation error because
    a user can\nenter code to excute arbitraury code and failure with code can lead
    to a denial of service. This seems\nto be a classic case of improper input validation
    because of the lack of input sanitization. The code \ndid have input validation
    before but it didn't account for chained expressions. This could be avoided in\nthe
    future by testing a greater range of possible expressions.\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: 
reported: '2016-06-20'
announced: '2016-06-20'
subsystem:
  name: core
  answer: |
    This bug affected the availability and integrity of the application that used the OgnlUtil.java class. Especially since
    arbituary code would be executed. This is in the opensymphony part of the repo in the core.
  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: '2016-06-20'
  answer: "Adam Mariš an employee at Red Hat found the bug. He reported it at this
    url (https://bugzilla.redhat.com/show_bug.cgi?id=1348238)\nand CC'd the appropriate
    Apache people. \n"
  apache: 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 Apache
    employee (you can tell from their email address). 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.
    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: "An attacker can execute code in the application. It is possible by passing
  \na malicious expression. If it didn't work a denial of service would ensue.\nA
  malicious expression could be added by chaining the expression to another,\nthis
  means the code would try to execute one of the expressions but ends up\ndoing both.\n"
unit_tested:
  fix: true
  code: true
  answer: |
    Yes it appears the code was unit tested since there is a test class for OgnlUtil.java (OgnlUtilTest.java)
    It also appears to have been updated with the code with the commit that solved the issue. https://github.com/apache/struts/blob/master/core/src/test/java/com/opensymphony/xwork2/ognl/OgnlUtilTest.java
  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: 1
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: S2-037
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 interesting commits found
  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: |
  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.