CVE-2004-2494 in Mail Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in _error in Ability Mail Server 1.18 allows remote attackers to inject arbitrary web script or HTML via the erromsg parameter.
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Analysis
by VulDB Data Team • 01/19/2025
The vulnerability identified as CVE-2004-2494 represents a classic cross-site scripting flaw within the Ability Mail Server 1.18 application. This security weakness resides in the error handling mechanism of the system, specifically within the _error component where user input is not properly sanitized before being rendered back to clients. The vulnerability manifests when the erromsg parameter is processed without adequate validation or encoding, creating an opportunity for malicious actors to inject arbitrary web scripts or HTML code into the application's response. This type of vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and well-documented web application security flaws in the industry.
The technical implementation of this vulnerability allows remote attackers to execute malicious code within the context of other users' browsers who visit affected pages. When a user encounters an error condition within the Ability Mail Server, the system displays an error message that includes the erromsg parameter directly in the HTML response. Attackers can craft malicious payloads that, when processed by the vulnerable application, get executed in the browsers of unsuspecting users. This creates a persistent threat vector where attackers can steal session cookies, perform unauthorized actions on behalf of users, or redirect victims to malicious websites. The vulnerability is particularly concerning because it operates entirely through standard HTTP requests without requiring any special privileges or authentication, making it highly exploitable in real-world scenarios.
The operational impact of this vulnerability extends beyond simple script execution, potentially enabling sophisticated attacks such as session hijacking, credential theft, and data exfiltration. Users who interact with the mail server's error pages become unwitting participants in the attack chain, as their browsers execute the injected malicious code. This vulnerability can be exploited through various vectors including crafted error conditions, malformed email content, or manipulated server responses that trigger the vulnerable error handling routine. The attack surface is broadened by the fact that this affects the core error handling mechanism, which would be invoked during normal server operation when users encounter various error conditions, making the exploitation more likely to occur in real-world environments.
Mitigation strategies for CVE-2004-2494 should focus on implementing proper input validation and output encoding mechanisms throughout the application's error handling pathways. The most effective approach involves sanitizing all user-provided input before it is processed or displayed, particularly in error messages and other dynamic content generation scenarios. Organizations should implement Content Security Policy headers to limit script execution capabilities and use proper HTML encoding techniques when rendering user data back to browsers. Additionally, upgrading to newer versions of the Ability Mail Server that address this vulnerability would provide the most comprehensive solution. The remediation aligns with ATT&CK technique T1566.001 for credential access through social engineering and T1584.003 for resource development through web application exploitation. Regular security testing and code reviews should specifically target error handling routines to prevent similar vulnerabilities from emerging in other components of the system, as the principles of secure input handling and output encoding are fundamental to preventing XSS attacks across all web applications.