Happy DOM has cookie scope forgery: no DNS-label boundary on Domain= matching , attacker origin sets victim cookies

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Prior to 20.14.6, Happy DOM's CookieContainer in src/cookie/CookieContainer.ts does not correctly validate or match Domain cookie attributes. It can accept a Domain unrelated to the origin setting the cookie, including a public suffix, and separately treats an unrelated suffix-sharing hostname as a match because cookieMatchesURL does not enforce a DNS-label boundary. In server-side rendering and prerendering applications that contact attacker-controlled origins and then make requests to a victim origin, these behaviors can plant and deliver a forged cookie, enabling cookie injection or session fixation. This issue is fixed in version 20.14.6.

[ Fixes ]Fixes and patches

• happy-dom 20.14.6Fixed version · GitHub Advisories · npm package happy-dom: upgrade to 20.14.6 or later (affected <= 20.14.5)

[ Packages ]Affected open-source packages

• happy-dom npmAffected <= 20.14.5 · fixed in 20.14.6 · GHSA-5fpq-26gf-qwcr

[ References ]References

• github.com/capricorn86/happy-dom/commit/f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3
• github.com/capricorn86/happy-dom/pull/2477
• github.com/capricorn86/happy-dom/releases/tag/v20.14.6
• github.com/capricorn86/happy-dom/security/advisories/GHSA-5fpq-26gf-qwcr