VULNERABILITY INTELLIGENCE

CVE-2020-3565

CVSS score5.8 MEDIUM
EPSS probability0.95%
CISA KEVNot currently listed
Published2020-10-21
Last modified2026-08-11
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Description

A vulnerability in the TCP Intercept functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Access Control Policies (including Geolocation) and Service Polices on an affected system. The vulnerability exists because TCP Intercept is invoked when the embryonic connection limit is reached, which can cause the underlying detection engine to process the packet incorrectly. An attacker could exploit this vulnerability by sending a crafted stream of traffic that matches a policy on which TCP Intercept is configured. A successful exploit could allow the attacker to match on an incorrect policy, which could allow the traffic to be forwarded when it should be dropped. In addition, the traffic could incorrectly be dropped.

Weakness classification

  • psirt@cisco.com: CWE-284
  • nvd@nist.gov: CWE-287

Primary references