CVE-2002-0950 in Active! Mail
Summary
by MITRE
Cross-site scripting vulnerability in TransWARE Active! mail 1.422 and 2.0 allows remote attackers to execute arbitrary code via a certain e-mail header, which is not properly filtered.
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Analysis
by VulDB Data Team • 09/10/2025
The vulnerability identified as CVE-2002-0950 represents a critical cross-site scripting flaw in TransWARE Active! mail versions 1.422 and 2.0 that fundamentally compromises the security of email client applications. This vulnerability exists within the email header processing mechanism where maliciously crafted email headers are not properly sanitized or filtered before being rendered in the user interface. The flaw allows remote attackers to inject malicious scripts that can execute in the context of the victim's browser when they view the affected email headers, creating a persistent threat vector that can be exploited across multiple email clients and platforms. The vulnerability operates at the application layer and specifically targets the email rendering engine's handling of untrusted input data, making it particularly dangerous in enterprise environments where email systems serve as primary communication channels.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the email header parsing functionality of TransWARE Active! mail. When the email client processes incoming messages with maliciously crafted headers, the application fails to properly escape or filter special characters that could be interpreted as HTML or JavaScript code. This insufficient sanitization creates a pathway for attackers to inject malicious scripts that execute within the user's browser context, potentially leading to session hijacking, data theft, or further compromise of the user's system. The vulnerability is classified as a CWE-79: Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly neutralize input data before it is rendered in web-based applications or email clients. The attack vector is particularly insidious because it requires no user interaction beyond simply viewing the malicious email header, making it a prime candidate for automated exploitation campaigns.
The operational impact of this vulnerability extends far beyond simple script execution, as it creates a persistent threat that can be leveraged for advanced persistent threats and credential theft. Attackers can craft emails containing malicious JavaScript that can steal user session cookies, redirect users to phishing sites, or even execute additional malicious payloads that can escalate privileges within the email client environment. The vulnerability's exploitation potential is further amplified by its ability to work across different email client versions and platforms, creating a wide attack surface that can be leveraged in targeted campaigns. Organizations using TransWARE Active! mail systems face significant risk of unauthorized access, data breaches, and potential system compromise, particularly in environments where email serves as a primary attack vector for social engineering campaigns. The vulnerability directly aligns with ATT&CK technique T1566.001: Phishing for Information, as it enables attackers to craft sophisticated phishing emails that can bypass traditional email filtering mechanisms and execute malicious code directly in the user's browser.
Mitigation strategies for this vulnerability require immediate implementation of multiple defensive measures including comprehensive input validation and output encoding for all email header processing functions. Organizations should implement strict header sanitization protocols that escape or remove potentially dangerous characters before rendering email content, which aligns with the security principle of defense in depth. The recommended approach includes deploying email filtering solutions that can detect and block malicious email headers, implementing web application firewalls to monitor for cross-site scripting attempts, and ensuring all email client software is updated to patched versions that properly address the input sanitization flaws. Additionally, user education regarding the risks of opening suspicious emails and the importance of maintaining updated security software should be emphasized. The vulnerability highlights the critical importance of proper input validation and output encoding in preventing cross-site scripting attacks, making it essential for organizations to review their email security implementations against established security frameworks and industry best practices.