GHSA-rq77-p4h8-4crw — csrf
Fix: gorilla/csrf@9dd6af1GHSA-rq77-p4h8-4crw is a Cross-Site Request Forgery (CSRF) vulnerability in github.com/gorilla/csrf. A fix is available for github.com/gorilla/csrf — see the affected versions and patch details below.
gorilla/csrf CSRF vulnerability due to broken Referer validation
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rq77-p4h8-4crw.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/gorilla/csrfReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
gorilla/csrf is vulnerable to CSRF via form submission from origins that share a top level domain with the target origin.
Details
gorilla/csrf does not validate the Origin header against an allowlist. Its executes its validation of the Referer header for cross-origin requests only when it believes the request is being served over TLS. It determines this by inspecting the r.URL.Scheme value. However, this value is never populated for "server" requests per the Go spec, and so this check does not run in practice.
// URL specifies either the URI being requested (for server
// requests) or the URL to access (for client requests).
//
// For server requests, the URL is parsed from the URI
// supplied on the Request-Line as stored in RequestURI. For
// most requests, fields other than Path and RawQuery will be
// empty. (See [RFC 7230, Section 5.3](https://rfc-editor.org/rfc/rfc7230.html#section-5.3))
//
// For client requests, the URL's Host specifies the server to
// connect to, while the Request's Host field optionally
// specifies the Host header value to send in the HTTP
// request.
URL *[url](https://pkg.go.dev/net/url).[URL](https://pkg.go.dev/net/url#URL)
PoC
- create trusted origin
target.example.testprotected with gorilla/csrf and served over TLS hosting form on/submit - create attacker origin
attack.example.testserved over TLS - attacker exfiltrates token & cookie combination from
target.example.test - attacker sets exfiltrated cookie with
domain=.example.test and path=/submit- as the cookie has a more specific path than
/(the default for CSRF cookies) it will be sent first by the browser on submit to our target origin
- as the cookie has a more specific path than
- submit form from
attack.example.testwith exfiltrated CSRF form token - observe valid form submission as
attack.example.testOrigin / Referer headers are not validated.
Impact
This vulnerability allows an attacker who has gained XSS on a subdomain or top level domain to perform authenticated form submissions against gorilla/csrf protected targets that share the same top level domain.
This bug has existed in gorilla/csrf since its initial release in 2015.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/gorilla/csrf | all versions | 1.7.3go get github.com/gorilla/csrf@v1.7.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/gorilla/csrf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/gorilla/csrf to 1.7.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rq77-p4h8-4crw is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-rq77-p4h8-4crw can be triaged on real exposure rather than presence alone.
Tailored to GHSA-rq77-p4h8-4crw. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rq77-p4h8-4crw in your dependencies?
O3 Security finds GHSA-rq77-p4h8-4crw across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.