name: browser-auth-flow description: Probe a site's authentication flow for redirect leaks, missing CSRF, weak session cookies, and OAuth misconfiguration; produces an auth findings.md argument-hint: "<login-url> [--credentials <handle>] [--probes csrf,redirect,cookie,oauth]" allowed-tools: mcp__claude-flow__browser_open mcp__claude-flow__browser_close mcp__claude-flow__browser_fill mcp__claude-flow__browser_type mcp__claude-flow__browser_click mcp__claude-flow__browser_wait mcp__claude-flow__browser_eval mcp__claude-flow__browser_snapshot mcp__claude-flow__browser_get-url mcp__claude-flow__aidefence_has_pii mcp__claude-flow__aidefence_scan Bash Read Write

Browser Auth Flow

Adversarial probe of a site's authentication. Drives the login flow once, records the trajectory, then runs a configurable set of probes against the captured artifacts and live page. Output is a structured findings.md inside the RVF container.

When to use

• Pre-deployment audit of a new auth flow.
• Investigating a suspected token leak or redirect issue.
• Establishing a baseline for ongoing regression checks.

Steps

1. Open a recorded session via browser-record.

2. Drive the auth flow as in browser-login (credentials come from --credentials <handle> referencing browser-cookies if the run is a re-auth probe).

3. Run probes:

   • csrf: inspect the login POST in the trajectory; verify a same-origin token field is present and non-empty.
   • redirect: watch browser_get-url after each nav for cross-origin redirects with auth state in the URL or fragment. Flag any token-bearing URL that crosses an origin boundary.
   • cookie: walk document.cookie via browser_eval. For each cookie, check Secure, HttpOnly, SameSite, expiry, and entropy of the value. Flag missing flags or short tokens. Pass each through aidefence_scan to flag PII embedded in cookie values.
   • oauth: if the flow involves a third-party provider, capture the authorization request, verify state and nonce are present and high-entropy, verify redirect_uri matches the registered callback domain.

4. Quarantine any token / credential / PII captured during probing — it stays inside the RVF container's findings, never returns to the model unredacted (aidefence_is_safe gate from browser-extract applies if you read the findings back).

5. Write findings.md with one section per probe, severity rating per finding, and a verdict (pass / warn / fail).

6. Index the session in browser-sessions with tag: auth-probe so future audits compare against it.

Caveats

• This skill probes; it does not exploit. Do not chain follow-up requests using a captured token.
• Credentials must come from a vaulted handle or interactive entry. Never hardcode them in the field map.
• Some probes require multiple page loads. Trajectory step count for an auth probe typically lands at 15–40 steps; budget accordingly.
• The output is structured for human review. Do not auto-act on findings without surfacing them to the user first.