Impact
@fastify/static is vulnerable to a bypass of route-based middleware and guards via non-leading .. and %2E%2E path segments. find-my-way does not normalize .. when matching routes, so a request such as /foo/../deep/secret.txt matches the static plugin's catch-all instead of the guarded /deep/*. The getPathnameForSend helper introduced by the fix for GHSA-x428-ghpx-8j92 only guards against the %2F variant; .. and %2E%2E survive the decodeURI + encodeURI round-trip and are then collapsed away by @fastify/send's path.normalize before its own traversal guard runs.
Applications that rely on route-based middleware or guards to protect files served by @fastify/static can be bypassed with non-leading dot-dot path segments.
Patches
Upgrade to @fastify/static 10.1.1.
Workarounds
Do not use route-based middlewares or guards to protect files served by @fastify/static.
References
imssm99 Reporter
mcollina Remediation developer
UlisesGascon Remediation reviewer
Impact
@fastify/staticis vulnerable to a bypass of route-based middleware and guards via non-leading..and%2E%2Epath segments.find-my-waydoes not normalize..when matching routes, so a request such as/foo/../deep/secret.txtmatches the static plugin's catch-all instead of the guarded/deep/*. ThegetPathnameForSendhelper introduced by the fix for GHSA-x428-ghpx-8j92 only guards against the%2Fvariant;..and%2E%2Esurvive thedecodeURI+encodeURIround-trip and are then collapsed away by@fastify/send'spath.normalizebefore its own traversal guard runs.Applications that rely on route-based middleware or guards to protect files served by
@fastify/staticcan be bypassed with non-leading dot-dot path segments.Patches
Upgrade to
@fastify/static10.1.1.Workarounds
Do not use route-based middlewares or guards to protect files served by
@fastify/static.References