GHSA-593f-38f6-jp5m

Inefficient Regular Expression Complexity in koa

At a glance

Published
Updated
CVE
CVE-2025-25200
CVSS_V4
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.

Affected packages

PackageVersions
npm · koaintroduced 2.0.0, fixed 2.15.4
npm · koaintroduced 3.0.0-alpha.0, fixed 3.0.0-alpha.3
npm · koaintroduced 1.0.0, fixed 1.7.1
npm · koaintroduced 0, fixed 0.21.2

References

Sources

SourceLicence
OSV.devCC-BY 4.0 — GitHub Advisory Database