# CVE-2025-40630: Open redirection vulnerability in IceWarp Mail Server

- Exploited (CISA KEV): no
- Published: 2025-05-16
- CVSS: 5.1 MEDIUM (v4.0)
- EPSS: 0.5% (43th percentile)
- CWE: CWE-601

Open redirection vulnerability in IceWarp Mail Server affecting version 11.4.0. This vulnerability allows an attacker to redirect a user to any domain by sending a malicious URL to the victim, for example “ https://icewarp.domain.com//<MALICIOUS_DOMAIN>/%2e%2e” https://icewarp.domain.com///%2e%2e” . This vulnerability has been tested in Firefox.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | No public claim | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2025-12-03 | 201 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### F5

- 2025-12-03 · new · rule 200018198
  > Added: signature 200018198 "IceWarp Open Redirect" (Other Application Attacks, risk Medium), systems: Other Web Server. References: CVE-2025-40630.
  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-2025-40630, 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-2025-40630, 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-2025-40630 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2025-40630