CVE-2007-4010 in PHP
Summary
by MITRE
The win32std extension in PHP 5.2.3 does not follow safe_mode and disable_functions restrictions, which allows remote attackers to execute arbitrary commands via the win_shell_execute function.
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Analysis
by VulDB Data Team • 09/28/2024
The vulnerability identified as CVE-2007-4010 represents a critical security flaw in PHP versions 5.2.3 and earlier, specifically within the win32std extension. This issue fundamentally undermines the security model that PHP implements to protect against unauthorized command execution, creating a dangerous pathway for remote attackers to bypass established security controls. The win32std extension was designed to provide Windows-specific functionality, including the win_shell_execute function that enables shell command execution on Windows systems. However, this extension failed to respect the fundamental security mechanisms that PHP provides to restrict dangerous operations.
The technical flaw resides in the improper implementation of access controls within the win32std extension, where the win_shell_execute function operates outside the normal security boundaries established by PHP's safe_mode and disable_functions directives. These mechanisms are standard PHP security features designed to prevent execution of potentially dangerous functions and to restrict access to system resources when PHP is running in safe mode. The vulnerability allows attackers to execute arbitrary commands on the target system regardless of whether safe_mode is enabled or whether specific functions have been disabled through the disable_functions configuration directive. This represents a complete bypass of PHP's intended security model for command execution.
The operational impact of this vulnerability is severe and far-reaching, as it enables remote command execution capabilities that can be exploited from outside the local network. Attackers can leverage this flaw to perform system-level operations including but not limited to executing arbitrary shell commands, accessing sensitive system files, modifying system configurations, and potentially escalating privileges to gain full control over the affected system. The vulnerability particularly affects Windows environments where the win32std extension is available and active, making it a significant concern for web servers running PHP on Windows platforms. This type of vulnerability directly maps to the CWE-284 weakness category, which deals with improper access control, and represents a critical failure in the principle of least privilege. The attack surface is particularly concerning as it allows for arbitrary code execution without requiring authentication or specific user privileges beyond normal web access.
Mitigation strategies for this vulnerability require immediate action including upgrading to PHP versions where this issue has been resolved, typically PHP 5.2.4 and later. System administrators should disable the win32std extension entirely if it is not required for application functionality, as this removes the attack vector entirely. Additionally, network-level firewalls should be configured to restrict access to PHP applications and web servers, while application-level security measures such as input validation and output encoding should be implemented to reduce the overall attack surface. The vulnerability demonstrates the importance of proper privilege separation and access control implementation in extension modules, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation. Organizations should also implement comprehensive monitoring and logging of system calls and command execution attempts to detect potential exploitation attempts. The vulnerability highlights the critical need for security reviews of extension modules and proper adherence to secure coding practices that respect the security boundaries established by core PHP functionality.