CVE-2002-2086 in SquirrelMail
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in magicHTML of SquirrelMail before 1.2.6 allow remote attackers to inject arbitrary web script or HTML via (1) "<<script" in unspecified input fields or (2) a javascript: URL in the src attribute of an IMG tag.
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Analysis
by VulDB Data Team • 08/30/2025
The vulnerability identified as CVE-2002-2086 represents a critical cross-site scripting flaw within the magicHTML component of SquirrelMail email client software versions prior to 1.2.6. This vulnerability falls under the CWE-79 category of Cross-Site Scripting and specifically manifests in the web-based email interface that users interact with through their browsers. The flaw exists in the input sanitization and output encoding mechanisms that fail to properly validate or escape user-supplied data before rendering it within the web application's HTML context. Attackers can exploit this weakness to inject malicious script code that executes in the context of other users' browsers who view the affected content, creating a persistent threat vector within the email application's user base.
The technical exploitation of this vulnerability occurs through two distinct attack vectors that leverage different aspects of HTML parsing and script execution. The first vector involves injecting the string "<<script" into unspecified input fields within the SquirrelMail interface, which bypasses basic input validation checks that might not properly handle malformed script tag sequences. The second vector targets the src attribute of IMG tags by using javascript: URLs, which exploits how browsers handle image loading and script execution contexts. Both attack methods rely on the application's failure to properly sanitize user input before incorporating it into dynamically generated HTML content, allowing malicious code to persist in the application's data storage and execute whenever legitimate users access the affected pages.
The operational impact of CVE-2002-2086 extends beyond simple script injection, creating a significant security risk for organizations relying on SquirrelMail for email communication. When successfully exploited, these vulnerabilities enable attackers to execute arbitrary JavaScript code in the browsers of other users, potentially leading to session hijacking, credential theft, data exfiltration, and the execution of additional malicious payloads. The attack surface is particularly concerning given that SquirrelMail is a widely used web-based email client that many organizations deploy for internal communications. The persistent nature of XSS vulnerabilities means that once exploited, malicious scripts can remain active in the application's database, continuously affecting all users who access the compromised content, making this vulnerability particularly dangerous for collaborative environments where users regularly exchange emails and HTML-formatted messages.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to SquirrelMail version 1.2.6 or later, which contains the necessary patches to address the input validation flaws. Additional protective measures include implementing strict content security policies that prevent script execution in email content, enabling proper HTML sanitization filters, and conducting thorough input validation across all user-facing application components. The vulnerability demonstrates the importance of proper output encoding and input validation practices, aligning with ATT&CK technique T1566 for initial access through malicious content delivery. Security teams should also consider implementing web application firewalls to detect and block suspicious script injection attempts, while regular security assessments should verify that similar vulnerabilities do not exist in other components of the email infrastructure. The incident highlights the critical need for comprehensive security testing of web applications, particularly those handling user-generated content, and emphasizes the importance of maintaining up-to-date software versions to protect against known exploitation vectors.