Cisco Secure Firewall Management Center Software HTML Injection Vulnerability

August 14, 2025 Yanac

A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to inject arbitrary HTML content into a device-generated document. 
This vulnerability is due to improper validation of user-supplied data. An attacker could exploit this vulnerability by submitting malicious content to an affected device and using the device to generate a document that contains sensitive information. A successful exploit could allow the attacker to alter the standard layout of the device-generated documents, read arbitrary files from the underlying operating system, and conduct server-side request forgery (SSRF) attacks. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (Read Only).

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. 
This advisory is available at the following link: <a href=”https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-html-inj-MqjrZrny”>https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-html-inj-MqjrZrny</a>

This advisory is part of the August 2025 release of the Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see <a href=”https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75415″>Cisco Event Response: August 2025 Semiannual Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication</a>.

Security Impact Rating: High

CVE: CVE-2025-20148Cisco Security AdvisoryRead More