koajs/koa · Security
Inefficient Regular Expression Complexity in koa
- GHSA ID
- GHSA-593f-38f6-jp5m
- CVE ID
- CVE-2025-25200
- Severity
- critical
- Published
- Updated
- CVSS v4
- 9.2 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Description
Summary
Koa uses an evil regex to parse the X-Forwarded-Proto and X-Forwarded-Host HTTP headers. This can be exploited to carry out a Denial-of-Service attack.
PoC
Coming soon.
Impact
This is a Regex Denial-of-Service attack and causes memory exhaustion. The regex should be improved and empty values should not be allowed.
CWEs
- CWE-1333 · Inefficient Regular Expression Complexity
References
- https://github.com/koajs/koa/security/advisories/GHSA-593f-38f6-jp5m ↗
- https://nvd.nist.gov/vuln/detail/CVE-2025-25200 ↗
- https://github.com/koajs/koa/commit/5054af6e31ffd451a4151a1fe144cef6e5d0d83c ↗
- https://github.com/koajs/koa/commit/5f294bb1c7c8d9c61904378d250439a321bffd32 ↗
- https://github.com/koajs/koa/commit/93fe903fc966635a991bcf890cfc3427d33a1a08 ↗
- https://github.com/koajs/koa/releases/tag/2.15.4 ↗
- https://github.com/advisories/GHSA-593f-38f6-jp5m ↗