CVE-2021-34754 Cisco Firepower Threat Defense Software Ethernet Industrial Protocol Policy Bypass Vulnerabilities
Unauthenticated remote attackers can bypass access control and intrusion policies by sending crafted ENIP packets to Cisco Firepower Threat Defense interfaces.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-34754?
CVE-2021-34754 is a medium-severity vulnerability in Cisco Secure Firewall Management Center, published on 27 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Multiple vulnerabilities in the payload inspection for Ethernet Industrial Protocol (ENIP) traffic for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured rules for ENIP traffic. These vulnerabilities are due to incomplete processing during deep packet inspection for ENIP packets. An attacker could exploit these vulnerabilities by sending a crafted ENIP packet to the targeted interface. A successful exploit could allow the attacker to bypass configured access control and intrusion policies that should be activated for the ENIP packet.
Weakness: CWE-284
Which versions are affected by CVE-2021-34754?
It affects 2 products.
Products include Cisco Secure Firewall Management Center, Cisco Secure Firewall Threat Defense.
How do I fix CVE-2021-34754?
No fix has been published for CVE-2021-34754 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-34754 being exploited?
There is no known exploitation of CVE-2021-34754 in the wild and no public exploit code.
Other vulnerabilities in Cisco Secure Firewall Management Center
- CVE-2026-20079 Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel
- CVE-2026-20131 Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data
- CVE-2026-20316 Cisco Secure Firewall Management Center Use of Hard-coded Password
- CVE-2025-20265 Cisco Secure Firewall Management Center Software Radius Remote Code Execution Vulnerability
- CVE-2024-20424 Command injection in Cisco Firepower Management Center
Sources
Also known as GHSA-3j6c-cpfp-ff5p.