Secure Firewall ASA and FTD

CVE-2021-1494: Multiple Cisco products are affected by a in Cisco Firepower Threat Defense Software, Cisco UTD SNORT IPS Engine Software

Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP.

Published

ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityMEDIUMCVSS 3.1 5.8
EPSS1.1%Chance of exploitation in 30 days
Public exploitNot tracked
FixNot yet

Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.

Affected and fixed versions

Product / branchFixed in
Cisco Firepower Threat Defense Software N/ASee the advisory
Cisco UTD SNORT IPS Engine Software 16.12See the advisory
Cisco UTD SNORT IPS Engine Software 16.12See the advisory
Cisco UTD SNORT IPS Engine Software 16.12See the advisory
Cisco UTD SNORT IPS Engine Software 16.12See the advisory
Cisco UTD SNORT IPS Engine Software 16.6See the advisory
Cisco UTD SNORT IPS Engine Software 16.6See the advisory
Cisco UTD SNORT IPS Engine Software 16.6See the advisory
Cisco UTD SNORT IPS Engine Software 16.6See the advisory
Cisco UTD SNORT IPS Engine Software 16.6See the advisory
Cisco UTD SNORT IPS Engine Software 17.1See the advisory
Cisco UTD SNORT IPS Engine Software 17.2See the advisory
Cisco UTD SNORT IPS Engine Software 17.3See the advisory
Cisco UTD SNORT IPS Engine Software 17.3See the advisory
Cisco UTD SNORT IPS Engine Software 3.17See the advisory
Cisco UTD SNORT IPS Engine Software 3.17See the advisory
Cisco UTD SNORT IPS Engine Software Fuji-16.9See the advisory
Cisco UTD SNORT IPS Engine Software Fuji-16.9See the advisory
Cisco UTD SNORT IPS Engine Software Fuji-16.9See the advisory
Cisco UTD SNORT IPS Engine Software Fuji-16.9See the advisory
Cisco UTD SNORT IPS Engine Software Fuji-16.9See the advisory
Cisco UTD SNORT IPS Engine Software Fuji-16.9See the advisory
Cisco UTD SNORT IPS Engine Software Denali-16.3See the advisory
Cisco UTD SNORT IPS Engine Software Denali-16.3See the advisory
Cisco UTD SNORT IPS Engine Software Denali-16.3See the advisory
Cisco UTD SNORT IPS Engine Software Denali-16.3See the advisory
Cisco UTD SNORT IPS Engine Software Denali-16.3See the advisory
Cisco UTD SNORT IPS Engine Software Everest-16.6See the advisory
Cisco UTD SNORT IPS Engine Software Everest-16.6See the advisory
Cisco UTD SNORT IPS Engine Software Everest-16.6See 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 detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect handling of specific HTTP header parameters. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass a configured file policy for HTTP packets and deliver a malicious payload.

Exploitation

The Cisco Product Security Incident Response Team (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.

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