title: Cisco Firepower Threat Defense Software Nonstandard Protocol Detection Bypass Vulnerability
description: A vulnerability in the protocol detection component of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to improper detection of the initial use of a protocol on a nonstandard port. An attacker could exploit this vulnerability by sending traffic on a nonstandard port for the protocol in use through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious requests to protected systems that would otherwise be blocked. Once the initial protocol flow on the nonstandard port is detected, future flows on the nonstandard port will be successfully detected and handled as configured by the applied policy.
problem types: CWE-264
affected:
{
product: Cisco Firepower Threat Defense Software
vendor: Cisco
versions:
lessThan: n/a, status: affected, version: unspecified, versionType: custom
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5.8
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: LOW
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
version: 3.0
]
exploits: 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.