# CVE-2023-40044: Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability

- Exploited (CISA KEV): yes, added 2023-10-05, known ransomware use
- Published: 2023-09-27
- CVSS: 10 CRITICAL (v3.1)
- EPSS: 90.4% (100th percentile)
- CWE: CWE-502

In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.

## 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 | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2023-10-10 | 13 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### F5

- 2023-10-10 · new · rule 200104871
  > Added: signature 200104871 "Progress WS_FTP Remote Code Execution" (Server Side Code Injection, risk High), systems: ASP.NET, Other Web Server. References: CVE-2023-40044.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog
- 2023-12-12 · new · rule 200104871
  > Added: signature 200104871 "Progress WS_FTP Remote Code Execution" (Server Side Code Injection, risk High), systems: ASP.NET, Other Web Server. References: CVE-2023-40044.
  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 1 requests blocked), template CVE-2023-40044, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 1 requests blocked), template CVE-2023-40044, 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-2023-40044 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2023-40044