CVE-2007-6348 in SquirrelMail
Summary
by MITRE
SquirrelMail 1.4.11 and 1.4.12, as distributed on sourceforge.net before 20071213, has been externally modified to create a Trojan Horse that introduces a PHP remote file inclusion vulnerability, which allows remote attackers to execute arbitrary code.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/30/2021
The vulnerability identified as CVE-2007-6348 represents a critical security flaw in SquirrelMail versions 1.4.11 and 1.4.12 that were distributed prior to December 13, 2007. This issue stems from a malicious modification to the software distribution that introduced a trojan horse component, fundamentally compromising the integrity of the application. The vulnerability specifically targets the remote file inclusion mechanism within the SquirrelMail framework, creating an exploitable condition that enables attackers to execute arbitrary code on affected systems. The malicious modification occurred during the software distribution process, making this a supply chain attack variant that undermines trust in the software distribution channel.
The technical implementation of this vulnerability exploits the PHP remote file inclusion functionality within SquirrelMail's codebase. When the application processes user input that is not properly sanitized, it can be tricked into including malicious PHP files from remote servers. This occurs because the vulnerable code does not adequately validate or filter input parameters that are used to determine which files to include. The flaw operates at the application level where untrusted input is directly incorporated into file inclusion directives, creating a pathway for attackers to inject and execute malicious code. The vulnerability is classified under CWE-88, which addresses improper neutralization of argument delimiters in a command, and CWE-94, which covers improper control of generation of code, making it a particularly dangerous combination that allows for arbitrary code execution.
The operational impact of CVE-2007-6348 is severe and far-reaching for organizations using affected SquirrelMail versions. Attackers can leverage this vulnerability to gain full control over compromised systems, potentially leading to complete system compromise, data exfiltration, and persistent backdoor access. The trojan horse component makes detection more challenging as it appears to be legitimate software while harboring malicious functionality. Organizations may experience unauthorized access to email accounts, potential data breaches, and the establishment of persistent command and control channels. The vulnerability affects not only the email server functionality but can also serve as a foothold for broader network infiltration, as compromised email servers often contain credentials and access information that can be used to escalate privileges within the network infrastructure.
Mitigation strategies for this vulnerability require immediate action to address the compromised software distribution and implement comprehensive security measures. Organizations should upgrade to patched versions of SquirrelMail that have been verified as legitimate and free from malicious modifications. The recommended approach includes verifying software integrity through checksums and digital signatures before installation, implementing proper input validation and sanitization within the application, and deploying web application firewalls to detect and prevent malicious file inclusion attempts. Security practitioners should also conduct thorough vulnerability assessments of all email infrastructure and implement monitoring to detect unauthorized access attempts. According to ATT&CK framework, this vulnerability maps to T1190 for exploit public-facing application and T1059 for command and script interpreter, highlighting the need for comprehensive defensive measures. Additionally, organizations should establish secure software distribution practices and implement software integrity verification mechanisms to prevent similar supply chain compromises in the future.