fix(mcp): redirect-URI laxity probe false positives and unbounded recursion - #8
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… risk Two bugs in the mcp-redirect-uri-laxity check: 1. isBroadRedirectURI flagged any non-https URI, including native-app custom URI schemes (myapp://callback) and RFC 8252 §8.3 loopback http://localhost — both are legitimate and explicitly allowed by the OAuth for Native Apps spec. Fix: allow custom schemes (anything other than http/https) and loopback http:// hosts. 2. findRedirectURIs was unbounded on deeply nested JSON: a response with 11+ levels of nesting would grow the call stack indefinitely. Fix: cap recursion at 10 levels via a depth counter.
The previous fix allowed any non-http/https scheme as a native-app custom URI (RFC 8252). javascript:, data:, and vbscript: are code injection vectors that OAuth servers should never accept as redirect URIs; flag them explicitly before reaching the RFC 8252 allowance.
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Two bugs in
mcp-redirect-uri-laxity1. False positives on valid native-app redirect URIs
isBroadRedirectURIflagged any non-httpsURI as broad. This produced false positives for:myapp://callback,urn:ietf:wg:oauth:2.0:oob) — explicitly permitted by RFC 8252 for native appshttp://localhost/callback,http://127.0.0.1/...) — permitted by RFC 8252 §8.3At the same time, dangerous code-injection schemes (
javascript:,data:,vbscript:) were silently allowed through the default branch.Fix:
2. Unbounded recursion on deeply nested JSON
findRedirectURIsrecursed without a depth limit. An adversarially crafted (or just unusually nested) OAuth metadata document could overflow the stack.Fix: Cap recursion at 10 levels via a depth counter passed through
findRedirectURIsAt.