CVE-2025-20306: 
Cisco Secure Firewall Management Center vulnerability analysis and mitigation

A vulnerability (CVE-2025-20306) was discovered in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software. The vulnerability was first published on August 14, 2025, and affects systems with lockdown mode enabled, which is disabled by default. This command injection vulnerability was discovered by Sanmith Prakash of Cisco during internal security testing (Cisco Advisory).

The vulnerability is classified as CWE-77 (Command Injection) with a CVSS v3.1 base score of 4.9 (Medium). The security flaw stems from insufficient input validation of certain HTTP request parameters that are sent to the web-based management interface. The vulnerability specifically affects the Cisco Secure FMC Software when lockdown mode is enabled (Cisco Advisory, NVD).

A successful exploitation of this vulnerability could allow an authenticated attacker with Administrator-level privileges to execute commands as the root user on the affected device. The impact is primarily focused on system integrity, as indicated by the CVSS metrics showing high impact for integrity (I:H) but no impact on confidentiality (C:N) or availability (A:N) (Cisco Advisory).

Cisco has released software updates that address this vulnerability. There are no workarounds available for this vulnerability. Organizations using affected versions of Cisco Secure FMC Software should upgrade to a fixed version. It's worth noting that when lockdown mode is disabled, Linux shell access, including root-level shell access, is readily available through the expert CLI command (Cisco Advisory).