CVE-2004-1735 in Sympa
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the create list option in Sympa 4.1.x and earlier allows remote authenticated users to inject arbitrary web script or HTML via the description field.
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Analysis
by VulDB Data Team • 06/14/2025
The CVE-2004-1735 vulnerability represents a critical cross-site scripting flaw within the Sympa mailing list management system affecting versions 4.1.x and earlier. This vulnerability specifically targets the create list functionality where authenticated users can manipulate the description field to inject malicious web scripts or HTML content. The flaw exists in the application's input validation mechanisms, failing to properly sanitize user-supplied data before rendering it within the web interface. This oversight creates a persistent security risk that can be exploited by attackers who have already gained authentication credentials to the system.
The technical nature of this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications. The vulnerability operates through the injection of malicious code into the description field during list creation, where the system fails to implement proper output encoding or input sanitization measures. When other users view the affected list description, their browsers execute the injected scripts within the context of the vulnerable application, potentially leading to session hijacking, data theft, or unauthorized actions performed on behalf of the victim. This type of vulnerability demonstrates a fundamental weakness in the application's security architecture regarding user input handling and output rendering processes.
The operational impact of CVE-2004-1735 extends beyond simple script injection, as it provides attackers with a vector for more sophisticated attacks within the Sympa environment. An authenticated attacker can leverage this vulnerability to execute malicious code in the context of other users' sessions, potentially gaining access to sensitive mailing list data, user credentials, or administrative functions. The vulnerability is particularly dangerous because it requires only authentication to the system, making it accessible to users who may not have elevated privileges but can still cause significant damage through social engineering or session manipulation attacks. This weakness undermines the trust model of the application and can lead to widespread compromise of the mailing list management infrastructure.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The most effective approach involves sanitizing all user inputs, particularly those used in dynamic content generation, and ensuring that any data rendered to web browsers is properly escaped or encoded to prevent script execution. Organizations should also consider implementing proper access controls and monitoring for suspicious activities related to list creation and modification. The remediation process requires updating to patched versions of Sympa, implementing web application firewalls, and conducting thorough security reviews of input handling mechanisms. Additionally, regular security training for administrators and users can help identify potential exploitation attempts and maintain overall system security posture. This vulnerability serves as a critical reminder of the importance of proper input validation and output encoding in web applications, aligning with ATT&CK technique T1059.001 for command and scripting interpreter execution through web-based attacks.