CVE-2017-5650

aka GOAWAY DoS

CVE: CVE-2017-5650
CWE: CWE-399
bugs: []
vccs:
- note: 
  commit: 
- note: 
  commit: 
fixes:
- note: Closes the streams as soon as the connection is closing. SVN rev 1788460,
    from the Tomcat website.
  commit: 5496e193a89b8b8b3177e516358df2f07ab852b3
- note: SVN rev 1788480, from the Tomcat website.
  commit: 2cb9c724e6a2d15a5bc909c4bf1ab9dfc26fa362
- note: 
  commit: 
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: Since this vulnerability is exploited by a DoS attack using malicious HTTP
      requests that bring the target system down, its clear that this vulnerability
      correlates with the concept of distrustful input.
    applies: true
  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: 
upvotes: 1
mistakes:
  answer: This vulnerability could have been easily avoided by doing proper penetration
    testing and making sure to evaluate all the different edge cases and applications
    for this software. It is imperative for software of this caliber to have a security
    design that avoids this kind of attacks. Thankfully, the fix involved few lines
    of code that addressed the issue without any further concerns. A more strict testing
    approach would have avoided this issue.
  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.
nickname: GOAWAY DoS
reported: '2017-03-24'
announced: '2017-04-10'
subsystem:
  name:
  - coyote
  - http2
  answer: http2
  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: '2017-03-24'
  answer: Chun Han Hsiao reported this vulnerability where he discovered that a remote
    user can consume excessive resources on the target system by sending a series
    of specially crafted HTTP/2 requests to trigger a flaw in the processing of HTTP/2
    GOAWAY frames and consume all available processing threads on the target system.
  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
    * 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: This CVE describes a Denial of Service attack done through the network
  via malicious HTTP requests, which are responsible for enabling communication between
  the client and the server. More specifically, the flaw can be encountered in the
  HTTP/2 GOAWAY frame. This component is responsible initiating shutdowns betweeen
  connections. This was exploited because its associated streams that were waiting
  for closure before allowing the application to write more data. These waiting streams
  each consumed a thread. Therefore, an attacker could generate a DoS attack through
  a malicious client that constructed a series of HTTP/2 requests that would consume
  all available processing thread, thus bringing the system down.
unit_tested:
  fix: false
  code: false
  answer: No unit tests were involved in the fix for this vulnerability. The fix involved
    modifying the handling of the HTTP/2 GOAWAY frame so that it would properly notify
    the WINDOW_UPDATE object, thus unit tests were not essential to this fix.
  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: Since no sources identify a public Vulnerability-Contributing Commit, no
    relation can be indicated between a VCC and the fix.
  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 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.