CVE-2002-1650 in SquirrelMail
Summary
by MITRE
The spell checker plugin (check_me.mod.php) for SquirrelMail before 1.2.3 allows remote attackers to execute arbitrary commands via a modified sqspell_command parameter.
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Analysis
by VulDB Data Team • 09/03/2025
The vulnerability described in CVE-2002-1650 represents a critical remote code execution flaw within the SquirrelMail webmail application's spell checker plugin. This vulnerability specifically affects versions of SquirrelMail prior to 1.2.3 and stems from improper input validation within the check_me.mod.php plugin file. The issue arises when the application fails to adequately sanitize user-supplied parameters, particularly the sqspell_command variable that controls spell checking operations. Attackers can exploit this weakness by crafting malicious input that modifies the sqspell_command parameter, thereby enabling arbitrary command execution on the affected server. The vulnerability demonstrates a classic command injection flaw that allows remote attackers to execute system commands with the privileges of the web server process, potentially leading to complete system compromise.
The technical implementation of this vulnerability involves the spell checker plugin's reliance on user-provided input without proper sanitization or validation before being passed to system execution functions. When the sqspell_command parameter is manipulated, it bypasses normal input filtering mechanisms and gets directly incorporated into system commands executed by the web application. This type of vulnerability maps directly to CWE-77 which describes improper neutralization of special elements used in commands, and specifically aligns with CWE-94 which addresses the execution of arbitrary code or commands. The attack vector operates through the web interface where users can interact with the spell checker functionality, making it accessible to remote attackers without requiring authentication or prior access to the system. The vulnerability essentially allows an attacker to inject malicious commands that the web server will execute as if they were legitimate system commands, creating a pathway for privilege escalation and system compromise.
From an operational impact perspective, this vulnerability poses severe risks to organizations relying on SquirrelMail for email services. Successful exploitation enables attackers to execute arbitrary commands on the target system, potentially allowing them to install backdoors, exfiltrate data, modify system files, or launch further attacks against internal networks. The remote nature of the attack means that threat actors can exploit this vulnerability from anywhere on the internet without requiring physical access or prior system compromise. This creates an immediate and significant security risk for any organization running vulnerable versions of SquirrelMail, particularly in environments where email services are exposed to untrusted networks. The vulnerability can be leveraged for persistent access, data theft, and as a foothold for broader network infiltration activities, making it a particularly dangerous flaw in web application security.
Organizations should prioritize immediate remediation by upgrading to SquirrelMail version 1.2.3 or later, which includes proper input validation and sanitization mechanisms for the spell checker plugin. System administrators should also implement network-level protections such as firewalls and intrusion detection systems to monitor for suspicious command execution patterns. Additional mitigations include disabling the spell checker plugin if it is not essential for operations, implementing web application firewalls to filter malicious input, and conducting regular security assessments of web applications. The vulnerability highlights the importance of input validation and proper sanitization in web applications, aligning with ATT&CK technique T1059.001 for command and script injection. Organizations should also consider implementing principle of least privilege for web server processes and regularly review and audit web application configurations to prevent similar vulnerabilities from being introduced in future deployments.