CVE-2025-20148 in Firepower Management Center
Summary
by MITRE • 08/14/2025
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).
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Analysis
by VulDB Data Team • 08/17/2025
The vulnerability identified as CVE-2025-20148 represents a critical security flaw within Cisco Secure Firewall Management Center software that enables authenticated remote attackers to perform HTML injection attacks against the web-based management interface. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing and rendering within device-generated documents. The vulnerability specifically affects the FMC software's handling of user input in contexts where HTML content is generated, creating opportunities for attackers to manipulate the presentation and functionality of system-generated reports and documentation. The flaw exists at the application layer within the web interface components responsible for document generation and rendering, making it particularly dangerous for organizations that rely heavily on automated reporting and documentation features.
The technical exploitation of this vulnerability requires an attacker to possess valid credentials with at least Security Analyst (Read Only) privileges, which demonstrates that the flaw operates within the context of authenticated sessions rather than being a purely remote attack vector. However, this authentication requirement does not mitigate the severity of the vulnerability since the attacker can leverage their legitimate access to manipulate the system's output generation mechanisms. The improper validation allows attackers to inject malicious HTML content that gets rendered within device-generated documents, potentially enabling multiple attack vectors including cross-site scripting scenarios, arbitrary file reads, and server-side request forgery operations. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically representing a server-side variant that can bypass client-side security controls. The attack surface expands significantly when considering that the affected system generates documents containing sensitive operational information, making the injection attacks particularly dangerous for information disclosure and privilege escalation scenarios.
The operational impact of this vulnerability extends beyond simple HTML injection, as successful exploitation can enable attackers to read arbitrary files from the underlying operating system, effectively bypassing traditional file access controls. This capability allows for the extraction of sensitive system information, configuration files, and potentially credentials stored within the system's file structure. The server-side request forgery component of the vulnerability creates additional attack vectors where attackers can use the FMC system as a pivot point to access internal network resources that would normally be isolated from external access. The combination of these attack vectors creates a multi-stage exploitation scenario that can lead to comprehensive system compromise and unauthorized access to protected network resources. Organizations utilizing Cisco FMC software face significant risk of data exfiltration, system reconnaissance, and potential lateral movement within their network infrastructure when this vulnerability remains unpatched.
Mitigation strategies for CVE-2025-20148 should prioritize immediate patch deployment from Cisco to address the root cause of the input validation issues. Organizations should implement network segmentation to limit access to the FMC management interface and restrict the number of users with Security Analyst privileges to reduce the attack surface. The principle of least privilege must be strictly enforced, ensuring that only authorized personnel have access to the affected system and that user accounts are regularly reviewed for appropriate access levels. Network monitoring should be enhanced to detect unusual document generation patterns or attempts to access system resources through the management interface. Additionally, organizations should implement web application firewalls and content filtering mechanisms to detect and block malicious HTML injection attempts. The vulnerability's classification under ATT&CK technique T1213 (Data from Information Repositories) and T1566 (Phishing) highlights the importance of comprehensive security monitoring and incident response procedures. Regular security assessments and penetration testing should be conducted to identify similar validation weaknesses in other system components and to ensure that the implemented mitigations remain effective against evolving attack techniques.