# CVE-2024-55591: Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability

- Exploited (CISA KEV): yes, added 2025-01-14, known ransomware use
- Published: 2025-01-14
- CVSS: 9.6 CRITICAL (v3.1)
- EPSS: 94.3% (100th percentile)
- CWE: CWE-288

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0 through 7.0.16 and FortiProxy version 7.0.0 through 7.0.19 and 7.2.0 through 7.2.12 allows a remote attacker to gain super-admin privileges via crafted requests to Node.js websocket module.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2025-02-18 | 35 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2025-06-30 | 167 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2025-02-18 · new · rule d1d45e4f59014f0fb22e0e6aa2ffa4b8 · default Block
  > FortiOS - Auth Bypass - CVE:CVE-2024-55591. Previous action: Log. New action: Block. This is a New Detection
  Source: https://developers.cloudflare.com/changelog/post/2025-02-18-waf-release/

### F5

- 2025-06-30 · new · rule 200013120
  > Added: signature 200013120 "FortiOS Authentication Bypass (2)" (Authentication/Authorization Attacks, risk High), systems: Other Web Server, Node.js, JavaScript. References: CVE-2024-55591.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog
- 2025-06-30 · new · rule 200013121
  > Added: signature 200013121 "FortiOS Authentication Bypass (3)" (Authentication/Authorization Attacks, risk High), systems: Other Web Server, Node.js, JavaScript. References: CVE-2024-55591.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog
- 2025-06-30 · new · rule 200013122
  > Added: signature 200013122 "FortiOS Authentication Bypass (4)" (Authentication/Authorization Attacks, risk High), systems: Other Web Server, Node.js, JavaScript. References: CVE-2024-55591.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 2 requests blocked), template CVE-2024-55591, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 2 requests blocked), template CVE-2024-55591, 2026-11-02

"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-2024-55591 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2024-55591