Secure Firewall ASA and FTD
CVE-2024-20339: Cisco Firepower Threat Defense Software for Firepower 2100 Series TLS Denial of Service Vulnerability
A vulnerability in the TLS processing feature of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
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 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | 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 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | 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 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | 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 6.4 | 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 6.6 | 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 6.4 | 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 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A vulnerability in the TLS processing feature of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to an issue that occurs when TLS traffic is processed. An attacker could exploit this vulnerability by sending certain TLS traffic over IPv4 through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition and impacting traffic to and through the affected device.
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.