CVE-2025-20217
Cisco Firepower Threat Defense Intrusion Detection Denial of Service Vulnerability
Description
A vulnerability in the packet inspection functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect processing of traffic that is inspected by an affected device. An attacker could exploit this vulnerability by sending crafted traffic through the affected device. A successful exploit could allow the attacker to cause the affected device to enter an infinite loop while inspecting traffic, resulting in a DoS condition. The system watchdog will restart the Snort process automatically.
Weakness: CWE-835
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Firepower Threat Defense (FTD) Check your version | Firewall / NGFW | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco Firepower Threat Defense Software
Vendor advisory
Cisco Secure Firewall Threat Defense Software Snort 3 Denial of Service Vulnerability
Cisco’s rating: High (advisory CVSS 8.6) · Published Aug 14, 2025
Bug ID: CSCwm44719
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from