# CVE-2024-45409: The Ruby SAML library vulnerable to a SAML authentication bypass via Incorrect XPath selector

- Exploited (CISA KEV): no
- Published: 2024-09-10
- CVSS: 10 CRITICAL (v3.1)
- EPSS: 10.7% (96th percentile)
- CWE: CWE-347

The Ruby SAML library is for implementing the client side of a SAML authorization. Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system. This vulnerability is fixed in 1.17.0 and 1.12.3.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Before feed history | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2024-11-12 | 63 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### F5

- 2024-11-12 · new · rule 200014040
  > Added: signature 200014040 "Gitlab SAML Authentication Bypass" (Abuse of Functionality, risk High), systems: Other Web Server, Ruby. References: CVE-2024-45409.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2024-45409 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2024-45409