Secure Firewall ASA and FTD
CVE-2023-20031: A vulnerability in the SSL/TLS certificate handling of Snort 3 Detection Engine integration with Cisco Fire…
A vulnerability in the SSL/TLS certificate handling of Snort 3 Detection Engine integration with Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 detection engine to restart.
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 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | 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 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 7.0 | 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 7.0 | 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 7.2 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A vulnerability in the SSL/TLS certificate handling of Snort 3 Detection Engine integration with Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 detection engine to restart. This vulnerability is due to a logic error that occurs when an SSL/TLS certificate that is under load is accessed when it is initiating an SSL connection. Under specific, time-based constraints, an attacker could exploit this vulnerability by sending a high rate of SSL/TLS connection requests to be inspected by the Snort 3 detection engine on an affected device. A successful exploit could allow the attacker to cause the Snort 3 detection engine to reload, resulting in either a bypass or a denial of service (DoS) condition, depending on device configuration. The Snort detection engine will restart automatically. No manual intervention is required.
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.