CVE-2025-20217CWE-835

Cisco Firepower Threat Defense Intrusion Detection Denial of Service Vulnerability

High · published August 14, 2025

CVSS v3.1
8.6
EPSS
1%
Percentile
53.3
In the wild
Unconfirmed
What it 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 record
Technical detail
CVSS v3.1
8.6 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00717 · 53.3th percentile
Weakness
CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')
Published
2025-08-14T16:28Z
EPSS history
Timeline
  • 14 AUG 16:28Z
    Cisco Firepower Threat Defense Intrusion Detection Denial of Service Vulnerability
    cvelistv5