Secure Firewall ASA and FTD
CVE-2024-20330: Cisco Firepower Threat Defense Software for Cisco Firepower 2100 Series TCP UDP Snort 2 and Snort 2 Denial of Service Vulnerability
A vulnerability in the Snort 2 and Snort 3 TCP and UDP detection engine of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause memory corruption, which could cause the Snort detection engine to restart unexpectedly.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.4 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.4 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.4 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A vulnerability in the Snort 2 and Snort 3 TCP and UDP detection engine of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause memory corruption, which could cause the Snort detection engine to restart unexpectedly.
This vulnerability is due to improper memory management when the Snort detection engine processes specific TCP or UDP packets. An attacker could exploit this vulnerability by sending crafted TCP or UDP packets through a device that is inspecting traffic using the Snort detection engine. A successful exploit could allow the attacker to restart the Snort detection engine repeatedly, which could cause a denial of service (DoS) condition. The DoS condition impacts only the traffic through the device that is examined by the Snort detection engine. The device can still be managed over the network. Note: Once a memory block is corrupted, it cannot be cleared until the Cisco Firepower 2100 Series Appliance is manually reloaded. This means that the Snort detection engine could crash repeatedly, causing traffic that is processed by the Snort detection engine to be dropped until the device is manually reloaded.
Exploitation
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 11 Oct 2026.