Secure Firewall ASA and FTD
CVE-2025-20360: Multiple Cisco Products Snort 3 MIME Denial of Service Vulnerability
Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder that 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 Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.1 | See the advisory |
| Cisco Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.1 | See the advisory |
| Cisco Cyber Vision 3.1 | See the advisory |
| Cisco Cyber Vision 3.2 | See the advisory |
| Cisco Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.2 | See the advisory |
| Cisco Cyber Vision 3.0 | See the advisory |
| Cisco Cyber Vision 3.2 | See the advisory |
| Cisco Cyber Vision 3.2 | See the advisory |
| Cisco Cyber Vision 3.2 | See the advisory |
| Cisco Cyber Vision 4.0 | See the advisory |
| Cisco Cyber Vision 4.0 | See the advisory |
| Cisco Cyber Vision 4.0 | See the advisory |
| Cisco Cyber Vision 4.0 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.2 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 4.3 | See the advisory |
| Cisco Cyber Vision 4.3 | See the advisory |
| Cisco Cyber Vision 4.3 | See the advisory |
| Cisco Cyber Vision 4.3 | See the advisory |
| Cisco Cyber Vision 4.4 | See the advisory |
| Cisco Cyber Vision 4.4 | See the advisory |
| Cisco Cyber Vision 4.4 | See the advisory |
| Cisco Cyber Vision 4.4 | See the advisory |
| Cisco Cyber Vision 4.1 | See the advisory |
| Cisco Cyber Vision 5.0 | See the advisory |
| Cisco Cyber Vision 5.0 | See the advisory |
| Cisco Cyber Vision 5.0 | See the advisory |
| Cisco Cyber Vision 5.1 | See the advisory |
| Cisco Cyber Vision 5.1 | See the advisory |
| Cisco Cyber Vision 5.1 | See the advisory |
| Cisco Cyber Vision 5.1 | See the advisory |
| Cisco Cyber Vision 5.2 | See the advisory |
| Cisco Cyber Vision 5.2 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.3 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.3 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.3 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.3 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.6 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.7 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.6 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart.
This vulnerability is due to a lack of complete error checking when the MIME fields of the HTTP header are parsed. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine unexpectedly restarts.
Exploitation
The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 11 Oct 2026.