fix(api): validate OAuth redirect + require non-empty state#24
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ralyodio merged 1 commit intoJul 2, 2026
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…leak / login CSRF)
Two bugs in the CoinPay OAuth flow (services/api/src/index.ts):
1. Open redirect / session-token exfiltration (HIGH). The 'redirect' query
param was stored and, after login, the fresh session token was appended to
it (`${redirect}#token=${sess}`) and the browser redirected there — with
no validation. ?redirect=https://evil.com leaks the victim's session token
to an attacker host. Add safeRedirect() (new redirect.ts) that only honors
same-origin absolute URLs or site-relative paths; everything else falls back
to the safe default.
2. OAuth state CSRF (MEDIUM). The callback checked `state !== cookie`, but a
missing cookie AND missing state param both read as undefined, so
`undefined !== undefined` is false and the check was bypassed. Require a
non-empty state that matches the cookie.
Adds redirect.test.ts (same-origin allowed; external / protocol-relative /
javascript: / cross-scheme rejected). Logic verified standalone.
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Problem
Two bugs in the CoinPay OAuth flow (
services/api/src/index.ts), see #23:redirectquery param was stored and, after login, the session token was appended to it and the browser redirected there — unvalidated.?redirect=https://evil.comleaks the victim's session token.state !== cookiepasses when both areundefined(missing cookie + missing state param).Fix
safeRedirect()(newredirect.ts) — only same-origin absolute URLs or site-relative paths are honored; external / protocol-relative /javascript:/ cross-scheme fall back to the default.statematching the cookie.Tests
redirect.test.ts(same-origin allowed; external,//evil.com,javascript:, cross-scheme, empty all rejected). Verified standalone.Fixes #23.