REXML ReDoS vulnerability
Date: 2024-10
Affected: rubygems/rexml
Attack vector: dos
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2024-49761
CWE: CWE-1333
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

### Impact The REXML gem before 3.3.9 has a ReDoS vulnerability when it parses an XML that has many digits between `&#` and `x...;` in a hex numeric character reference (`&#x...;`). This does not happen with Ruby 3.2 or later. Ruby 3.1 is the only affected maintained Ruby. Note that Ruby 3.1 will reach EOL on 2025-03. ### Patches The REXML gem 3.3.9 or later include the patch to fix the vulnerability. ### Workarounds Use Ruby 3.2 or later instead of Ruby 3.1. ### References * https://www.ruby-lang.org/en/news/2024/10/28/redos-rexml-cve-2024-49761/: An announce on www.ruby-lang.org


Mitigations:

Architectural layers (MAESTRO):