# CVE-2025-20363: Cisco IOS

- Exploited (CISA KEV): no
- Published: 2025-09-25
- CVSS: 9 CRITICAL (v3.1)
- EPSS: 6.9% (94th percentile)
- CWE: CWE-122

A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. 

 This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device.

 For more information about this vulnerability, see the Details ["#details"] section of this advisory.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2025-09-28 | 3 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | No public claim | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2025-09-28 · new · rule a1bef4ada0b146d2862cad439ee0ab84 · default Disabled
  > Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363. Previous action: N/A. New action: Disabled. This is a New Detection
  Source: https://developers.cloudflare.com/changelog/post/2025-09-28-emergency-waf-release/
- 2025-09-28 · new · rule 51de6ce6596a40eb8200452ad30f768e · default Disabled
  > Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363. Previous action: N/A. New action: Disabled. This is a New Detection
  Source: https://developers.cloudflare.com/changelog/post/2025-09-28-emergency-waf-release/
- 2025-10-07 · new · rule 12f808a5315441688f3b7c8a3a4d1bd6 · default Block
  > Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363. Previous action: N/A. New action: Block. This is a New Detection
  Source: https://developers.cloudflare.com/changelog/post/2025-10-07-emergency-waf-release/

"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-2025-20363 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2025-20363