CVE-2022-20751: Cisco Firepower Threat Defense Software Snort Out of Memory Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-05-03 · updated 2026-08-11
Weakness: CWE-770

Description

A vulnerability in the Snort detection engine integration for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause unlimited memory consumption, which could lead to a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient memory management for certain Snort events. An attacker could exploit this vulnerability by sending a series of crafted IP packets that would generate specific Snort events on an affected device. A sustained attack could cause an out of memory condition on the affected device. A successful exploit could allow the attacker to interrupt all traffic flowing through the affected device. In some circumstances, the attacker may be able to cause the device to reload, resulting in a DoS condition.

Affected products

Cisco Firepower Threat Defense Software: before 6.4.0.15; from 6.5.0 before 6.6.5.2; from 7.0.0 before 7.0.2; 7.1.0.0 — fixed in 6.4.0.15, 6.6.5.2, 7.0.2

How to fix

Upgrade to a fixed version: Cisco Firepower Threat Defense Software 6.4.0.15, 6.6.5.2, 7.0.2. Check the vendor advisory for mitigations.

References

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