VC005A01:2021·CWE-352

Missing CSRF protection

Cross-Site Request Forgery (CSRF) — state-changing routes that don't verify the request came from your own frontend.

What this rule detects

VC005 flags POST/PUT/DELETE/PATCH routes that mutate user state without a CSRF token check or `SameSite=Strict` cookie configuration. The rule excludes routes that are explicitly cross-origin by design (public webhooks, API endpoints with API-key auth).

Vulnerable vs. safe code

Vulnerable
// User visits attacker.com — attacker page submits a form to /api/delete-account.
app.post("/api/delete-account", async (req, res) => {
  await db.user.delete({ where: { id: req.session.userId } });
  res.json({ ok: true });
});
Safe
// Option 1: SameSite=Strict cookies (modern browsers, easiest).
app.use(session({
  cookie: { sameSite: "strict", secure: true, httpOnly: true },
}));

// Option 2: explicit CSRF token (defense in depth).
import csrf from "csurf";
app.use(csrf({ cookie: true }));

app.post("/api/delete-account", async (req, res) => {
  // csurf validates the token automatically; req.csrfToken() generates one
  // for the form/fetch call.
  await db.user.delete({ where: { id: req.session.userId } });
  res.json({ ok: true });
});

About A01:2021Broken Access Control

Access-control bugs let users do things they shouldn't — view another user's data, modify records they don't own, or hit admin-only endpoints without admin rights. This class moved to #1 in the 2021 OWASP Top 10 because 94% of audited apps had at least one access-control flaw.

Impact: An attacker who finds an access-control bug typically gets a much bigger blast radius than other vulnerability classes. Examples we've seen in AI-generated code: a /api/user/[id] route that returns any user's profile, a delete endpoint that doesn't check ownership, an admin dashboard with no role check.

How to fix it: Check authentication AND authorization on every server-side route. Never rely on the client to enforce permissions. Default to deny. For per-resource checks, fetch the resource and verify the requesting user owns it before returning or modifying it.

Common patterns in this category:

  • Missing auth check on API routes (the resource is returned to anyone with the URL)
  • Authorization based on a parameter the client controls (e.g. trusting `?userId=` in the URL)
  • Direct object references where the resource ID isn't validated against the requesting user
  • Public access to administrative or internal endpoints
  • Privilege escalation via mass assignment (user POSTs `{role: 'admin'}` and the ORM accepts it)

Compliance coverage

Findings from this rule map to the following framework controls:

SOC 2
CC6.1, CC6.6
ISO 27001
A.8.26, A.8.25
OWASP Top 10
A01:2021Broken Access Control
CWE
CWE-352

See the full compliance coverage page for how XploitScan maps every rule to SOC 2, ISO 27001, and OWASP Top 10 controls.

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Related rules in A01:2021

VC005: Missing CSRF protection | XploitScan Rules