CVE-2022-20751

Cisco Firepower Threat Defense Software Snort Out of Memory Denial of Service Vulnerability

HIGH

7.5

CVSS Score

Published: May 3, 2022 at 03:15 AM UTC

Updated: August 11, 2026 at 07:37 PM UTC

23 products affected across 1 vendorSecure Firewall Threat DefenseFirepower 4140Firepower 4110

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Severity

HIGH7.5

Exploit prediction

EPSS 1%

SSVC

No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Secure Firewall Threat Defense · Cisco

95%

v < 6.4.0.156.5.0 ≤ v < 6.6.5.27.0.0 ≤ v < 7.0.27.1.0.0

cisco-firepower-1000 (environment) · cisco-firepower-1010 (environment) · cisco-firepower-1020 (environment) · cisco-firepower-1030 (environment) · cisco-firepower-1040 (environment) · cisco-firepower-1120 (environment) · cisco-firepower-1140 (environment) · cisco-firepower-1150 (environment) · cisco-firepower-2100 (environment) · cisco-firepower-2110 (environment) · cisco-firepower-2120 (environment) · cisco-firepower-2130 (environment) · cisco-firepower-2140 (environment) · cisco-firepower-4100 (environment) · cisco-firepower-4110 (environment) · cisco-firepower-4112 (environment) · cisco-firepower-4115 (environment) · cisco-firepower-4120 (environment) · cisco-firepower-4125 (environment) · cisco-firepower-4140 (environment) · cisco-firepower-4145 (environment) · cisco-firepower-4150 (environment)

Firepower 1000 · Ciscodevice

80%

All versions

Firepower 1010 · Ciscodevice

80%

All versions

Firepower 1020 · Ciscodevice

80%

All versions

Firepower 1030 · Ciscodevice

80%

All versions