SurrealDB: SSRF via JWKS URL — Redirect Following in JWT Key Fetch

SurrealDB fetches the JWKS document for a JWT or record access method using a bare reqwest client that follows HTTP redirects by default. The network capability check in core/src/iam/jwks.rs (check_capabilities_url) is applied only to the originally configured URL; redirect targets are not re-validated. An --allow-net-permitted JWKS host that returns a 3xx Location can therefore redirect the request to an address the allowlist was meant to block, resulting in a server-side request forgery (SSRF). The protected HttpClient used by http::* functions re-checks every redirect hop and was hardened in 3.1.0, but the JWKS fetcher uses its own client and was not covered.

Impact

What an attacker can do:

• With the Owner role at database level or above (the minimum required to run DEFINE ACCESS ... TYPE JWT URL or TYPE RECORD ... WITH JWT URL), point an access method at an allowlisted host they control and redirect the server's GET to an otherwise-blocked target — cloud metadata, loopback, internal services — bypassing --allow-net/--deny-net.
• Infer the existence and liveness of internal hosts and ports from response-timing differences (bounded by the 1-second fetch timeout).

What it can't do:

• Read the response: the fetch is blind — the body is only parsed as a JWKS, and a non-JWKS response surfaces as an opaque InvalidAuth error. Nothing is returned to the caller.
• Modify data or affect availability (a single GET request).

Patches

The JWKS fetcher now applies a redirect policy that re-validates every redirect target against the configured network capabilities (mirroring check_capabilities_url) and caps redirects at max_http_redirects.

• Versions prior to 3.1.5 are vulnerable.

Workarounds

• Restrict the Owner role to trusted operators.
• Enforce egress filtering at the network layer (block link-local 169.254.0.0/16 and internal ranges) so redirect targets are unreachable regardless of in-process checks.
• Configure access methods to use only trusted JWKS hosts that do not redirect, or use locally defined keys instead of a remote JWKS.

References

• SurrealDB Documentation — Capabilities
• SurrealQL Documentation — DEFINE ACCESS
• fix(iam): prevent SSRF in JWKS fetch by re-validating redirect targets