Cisco Firepower Threat Defense Software up to 7.6.0 Snort 3 Detection Engine infinite loop

Summaryinfo

A vulnerability has been found in Cisco Firepower Threat Defense Software and classified as problematic. This impacts an unknown function of the component Snort 3 Detection Engine. This manipulation causes infinite loop. This vulnerability is tracked as CVE-2025-20217. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Cisco Firepower Threat Defense Software and classified as critical. Affected by this vulnerability is an unknown part of the component Snort 3 Detection Engine. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2025-20217 since 10/10/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1843). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Cisco Secure Firewall Threat Defense

Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Firepower Threat Defense Software

Version

• 7.1.0
• 7.1.0.1
• 7.1.0.2
• 7.1.0.3
• 7.2.0
• 7.2.0.1
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.4.1
• 7.2.5
• 7.2.5.1
• 7.2.5.2
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.8.1
• 7.2.9
• 7.3.0
• 7.3.1
• 7.3.1.1
• 7.3.1.2
• 7.4.0
• 7.4.1
• 7.4.1.1
• 7.4.2
• 7.4.2.1
• 7.6.0

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

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Entryinfo

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