CVE-2025-25200

HIGH

Koa <0.21.2, 1.7.1, 2.15.4, 3.0.0-alpha.3 - DoS

Title source: llm

Description

Koa is expressive middleware for Node.js using ES2017 async functions. Prior to versions 0.21.2, 1.7.1, 2.15.4, and 3.0.0-alpha.3, 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. Versions 0.21.2, 1.7.1, 2.15.4, and 3.0.0-alpha.3 fix the issue.

Exploits (1)

nomisec WORKING POC

by dwictor0 · poc

https://github.com/dwictor0/PoC-CVE-2025-25200

View Code ZIP pw:eip

References (7)

[Product] https://github.com/koajs/koa/blob/master/lib/request.js#L259

[Product] https://github.com/koajs/koa/blob/master/lib/request.js#L404

View Writeup ZIP pw:eip

[Patch] https://github.com/koajs/koa/commit/5054af6e31ffd451a4151a1fe144cef6e5d0d83c

[Patch] https://github.com/koajs/koa/commit/5f294bb1c7c8d9c61904378d250439a321bffd32

[Patch] https://github.com/koajs/koa/commit/93fe903fc966635a991bcf890cfc3427d33a1a08

[Release Notes] https://github.com/koajs/koa/releases/tag/2.15.4

[Vendor Advisory] https://github.com/koajs/koa/security/advisories/GHSA-593f-38f6-jp5m

Scores

CVSS v3 7.5

EPSS 0.0036

EPSS Percentile 57.9%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Details

CWE

CWE-1333

Status published

Products (3)

koajs/koa 3.0.0 alpha0 (3 CPE variants)

koajs/koa < 0.21.2

npm/koa 2.0.0 - 2.15.4npm

Published Feb 12, 2025

Tracked Since Feb 18, 2026