CVE-2021-34764: Cisco Firepower Management Center Virtual Appliance

Medium severity, CVSS 6.1. EPSS: 0.6% chance of exploitation in the next 30 days.

Multiple vulnerabilities in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an attacker to execute a cross-site scripting (XSS) attack or an open redirect attack. For more information about these vulnerabilities, see the Details section of this advisory.

Affected products

• Cisco Firepower Management Center Virtual Appliance: version 6.1.0 only; version 6.2.0 only; version 6.2.3 only; version 6.3.0 only; version 6.4.0 only; version 6.5.0 only; …
• Cisco Secure Firewall Threat Defense: before 6.4.0.13 (fixed in 6.4.0.13); from 6.5.0, before 6.6.5 (fixed in 6.6.5); from 6.7.0, before 6.7.0.3 (fixed in 6.7.0.3)
• Cisco Sourcefire Defense Center: version 6.1.0 only; version 6.2.0 only; version 6.2.3 only; version 6.3.0 only; version 6.4.0 only; version 6.5.0 only; …

Published 2021-10-27. Last modified 2026-08-11.