CVE-2019-25424 in Comodo Dome Firewall
Summary
by MITRE • 02/19/2026
Comodo Dome Firewall 2.7.0 contains a reflected cross-site scripting vulnerability that allows attackers to inject malicious scripts by submitting unsanitized input to the EXCEPTIONSITELIST parameter. Attackers can craft POST requests to the https_exceptions endpoint with script payloads to execute arbitrary JavaScript in users' browsers and steal session data.
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Analysis
by VulDB Data Team • 02/19/2026
The vulnerability identified as CVE-2019-25424 affects Comodo Dome Firewall version 2.7.0 and represents a critical reflected cross-site scripting flaw that fundamentally compromises web application security. This vulnerability resides within the firewall's web interface handling mechanism, specifically in how it processes user input through the EXCEPTIONSITELIST parameter. The flaw allows attackers to inject malicious scripts by crafting specially formatted POST requests to the https_exceptions endpoint, making it particularly dangerous as it operates within the context of legitimate user sessions.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the Comodo Dome Firewall's web administration interface. When the application receives a POST request containing the EXCEPTIONSITELIST parameter, it fails to properly sanitize or escape the input before incorporating it into the web response. This reflected XSS vulnerability occurs because the application directly echoes user-supplied data back to the browser without proper encoding or validation mechanisms. The vulnerability is classified under CWE-79 as a failure to sanitize user input, and it aligns with ATT&CK technique T1203 which covers exploitation of web application vulnerabilities for session hijacking.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to establish persistent access to user sessions and potentially escalate privileges within the firewall management interface. When successful, attackers can execute arbitrary JavaScript code in the context of authenticated users' browsers, enabling them to steal session cookies, modify firewall configurations, or redirect users to malicious sites. The reflected nature of the vulnerability means that the attack payload must be delivered through a crafted link or form submission, making it particularly effective for social engineering campaigns. Attackers can leverage this vulnerability to gain unauthorized access to the firewall's administrative functions, potentially compromising the entire network security infrastructure that the firewall is designed to protect.
Mitigation strategies for CVE-2019-25424 require immediate implementation of input validation and output encoding mechanisms within the Comodo Dome Firewall application. Organizations should implement proper parameter sanitization for all user-supplied input, particularly for parameters like EXCEPTIONSITELIST that are processed within web responses. The recommended approach includes implementing strict input validation that rejects or encodes potentially malicious characters, combined with output encoding that ensures any user-supplied data is properly escaped before being rendered in web pages. Additionally, organizations should consider implementing Content Security Policy headers to limit script execution and prevent unauthorized code injection. The vulnerability demonstrates the critical importance of secure coding practices and input validation in web applications, particularly those handling sensitive security functions. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other firewall components and ensure comprehensive protection against cross-site scripting attacks.