CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
AI Score
Confidence
High
I sent my original report here: https://hackerone.com/reports/2490560
REXML had a vulnerability where repeated >
characters in an attribute value took a very long time for the parser to finish.
The wait times increased exponentially the larger the string.
Reduced performance or Denial of Service was possible where REXML is used to parse user input.
Rails uses REXML to convert XML to a hash, so this was susceptible:
Hash.from_xml(request.body.read)