CVE-2007-6550 in Pmos Helpdesk
Summary
by MITRE
form.php in PMOS Help Desk 2.4 and earlier sends a redirect to the web browser but does not exit, which allows remote attackers to conduct eval injection attacks and execute arbitrary PHP code via the options array parameter.
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Analysis
by VulDB Data Team • 10/13/2024
The vulnerability identified as CVE-2007-6550 affects PMOS Help Desk version 2.4 and earlier, specifically within the form.php component. This issue represents a critical security flaw that stems from improper handling of user input and inadequate program flow control during HTTP redirects. The vulnerability manifests when the application processes the options array parameter without proper sanitization or termination of execution flow, creating an exploitable condition that can be leveraged by remote attackers to execute arbitrary code on the affected system.
The technical root cause of this vulnerability lies in the application's failure to properly exit the script execution after performing a redirect operation. When a redirect is issued to the web browser, the PHP script continues to execute subsequent code blocks, allowing an attacker to manipulate the options array parameter to inject malicious PHP code that gets evaluated and executed. This behavior creates a classic code injection vulnerability where the attacker can bypass normal input validation mechanisms and directly influence the application's execution flow. The flaw demonstrates poor secure coding practices and violates fundamental principles of input validation and program flow management that are essential for preventing injection attacks.
From an operational perspective, this vulnerability presents a severe risk to systems running affected PMOS Help Desk versions, as it allows remote attackers to execute arbitrary PHP code with the privileges of the web server process. The attack vector requires no authentication and can be performed through a simple web request containing the malicious options array parameter. This makes the vulnerability particularly dangerous as it can be exploited by anyone with access to the web application, potentially leading to complete system compromise, data exfiltration, or further lateral movement within the network. The impact extends beyond immediate code execution to include potential persistence mechanisms and privilege escalation opportunities that attackers can leverage to maintain long-term access to compromised systems.
The vulnerability aligns with CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and specifically relates to improper handling of input data that leads to code evaluation. This weakness is further categorized under the ATT&CK framework as part of the Code Injection tactic, where adversaries use various methods to execute malicious code on target systems. The lack of proper exit handling after redirect operations demonstrates a failure to implement proper program termination semantics that would prevent subsequent code execution. Organizations should implement immediate mitigations including upgrading to patched versions of PMOS Help Desk, implementing proper input validation for all user-supplied parameters, and configuring web application firewalls to detect and block suspicious parameter patterns. Additionally, the incident highlights the importance of following secure coding guidelines such as those outlined in the OWASP Top Ten and the CERT Secure Coding Standards to prevent similar vulnerabilities in future development efforts.