Vulnerability · Published May 13, 2025 · Assigned by GitHub_M
CVE-2025-46721nosurf vulnerable to CSRF due to non-functional same-origin request checks
Medium 6.0
In plain English
A medium-severity cross-site request forgery in nosurf from justinas. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
nosurf is cross-site request forgery (CSRF) protection middleware for Go. A vulnerability in versions prior to 1.2.0 allows an attacker who controls content on the target site, or on a subdomain of the target site (either via XSS, or otherwise) to bypass CSRF checks and issue requests on user's behalf. Due to misuse of the Go `net/http` library, nosurf categorizes all incoming requests as plain-text HTTP requests, in which case the `Referer` header is not checked to have the same origin as the target webpage. If the attacker has control over HTML contents on either the target website (e.g. `example.com`), or on a website hosted on a subdomain of the target (e.g. `attacker.example.com`), they will also be able to manipulate cookies set for the target website. By acquiring the secret CSRF token from the cookie, or overriding the cookie with a new token known to the attacker, `attacker.example.com` is able to craft cross-site requests to `example.com`. A patch for the issue was released in nosurf 1.2.0. In lieu of upgrading to a patched version of nosurf, users may additionally use another HTTP middleware to ensure that a non-safe HTTP request is coming from the same origin (e.g. by requiring a `Sec-Fetch-Site: same-origin` header in the request).
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/justinas/nosurf | 1.2.0 | GHSA-w9hf-35q4-vcjw |
| Go | github.com/justinas/nosurf | 1.2.0 | GO-2025-3683 |
Affected products (as reported)
Weakness: CWE-352 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/justinas/nosurf/security/advisories/GHSA-w9hf-35q4-vcjw x_refsource_CONFIRM
- https://github.com/justinas/nosurf/commit/ec9bb776d8e5ba9e906b6eb70428f4e7b009feee x_refsource_MISC
- https://github.com/advisories/GHSA-rq77-p4h8-4crw x_refsource_MISC
- https://github.com/justinas/nosurf-cve-2025-46721 x_refsource_MISC
- https://github.com/justinas/nosurf/releases/tag/v1.2.0 x_refsource_MISC