REXML ReDoS vulnerability

CVE-2024-49761 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

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

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2024-10-28 14:10:18 UTC
Updated
2025-11-03 22:49:25 UTC
GitHub reviewed
2024-10-28 14:10:18 UTC
NVD published
2024-10-28

EPSS Score

Score Percentile
0.90% 75.55%

CVSS Scores

Base score Version Severity Vector
7.5 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
6.6 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:U)
Unreported: no public PoC, no reported exploitation, and no known simplification tools.

Identifiers

Type Value
GHSA GHSA-2rxp-v6pw-ch6m ↗
CVE CVE-2024-49761 ↗

CWEs

CWE id Name
CWE-1333 Inefficient Regular Expression Complexity

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
rubygems rexml < 3.3.9 3.3.9 —

References

cvelogic Threat Intelligence