CVE-2002-2331 in W3Mail
Summary
by MITRE
W3Mail 1.0.2 through 1.0.5 with server side scripting (SSI) enabled in the attachments directory does not properly restrict the types of files that can be uploaded as attachments, which allows remote attackers to execute arbitrary code by sending code in MIME attachments, then requesting the attachments.
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Analysis
by VulDB Data Team • 07/13/2024
The vulnerability identified as CVE-2002-2331 affects W3Mail versions 1.0.2 through 1.0.5 when server side scripting capabilities are enabled in the attachments directory. This represents a critical security flaw that stems from inadequate input validation and file type restrictions within the email server's attachment handling mechanism. The vulnerability occurs when the system fails to properly validate the content and file extensions of uploaded attachments, creating an avenue for malicious code execution.
The technical flaw manifests through improper file type filtering in the server side includes directory where attachments are processed. When SSI functionality is enabled, the system becomes susceptible to code injection attacks as attackers can upload malicious files that contain server side scripting code. The vulnerability leverages the fact that the application does not adequately distinguish between legitimate attachments and potentially harmful code-containing files. This weakness directly maps to CWE-434 which describes insecure file upload vulnerabilities where applications accept files without proper validation of their content or type.
The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code on the affected server. Attackers can craft MIME attachments containing malicious code and upload them through the email system. Once uploaded and accessed, these files can be executed by the web server, potentially leading to complete system compromise. The attack vector is particularly dangerous because it utilizes legitimate email functionality to deliver malicious payloads, making detection more difficult. This vulnerability aligns with ATT&CK technique T1190 which describes the use of exploits for code execution through server-side includes and file upload mechanisms.
The security implications extend beyond immediate code execution to include potential data breaches, system infiltration, and lateral movement within networks. An attacker who successfully exploits this vulnerability can gain unauthorized access to the email server and potentially use it as a foothold for further attacks. The vulnerability affects the integrity and confidentiality of the email system's data and can be exploited to establish persistent access. Organizations using affected W3Mail versions face significant risk of unauthorized system access and potential data loss.
Mitigation strategies should focus on implementing strict file type validation and content filtering mechanisms. System administrators should disable SSI functionality in attachment directories when not absolutely necessary, as this removes a key attack vector. Implementing comprehensive file extension filtering, content type checking, and file signature validation can prevent malicious code uploads. Additionally, deploying web application firewalls and intrusion detection systems can help detect and block suspicious file upload attempts. Regular security updates and patches should be applied to address known vulnerabilities, while network segmentation and access controls can limit the potential damage from successful exploitation attempts.