CVE-2007-4586 in PHP
Summary
by MITRE
Multiple buffer overflows in php_iisfunc.dll in the iisfunc extension for PHP 5.2.0 and earlier allow context-dependent attackers to execute arbitrary code, probably during Unicode conversion, as demonstrated by a long string in the first argument to the iis_getservicestate function, related to the ServiceId argument to the (1) fnStartService, (2) fnGetServiceState, (3) fnStopService, and possibly other functions.
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Analysis
by VulDB Data Team • 10/01/2024
The vulnerability described in CVE-2007-4586 represents a critical buffer overflow flaw within the iisfunc extension for PHP versions 5.2.0 and earlier. This issue specifically affects the php_iisfunc.dll library which provides functions for interacting with Microsoft Internet Information Services. The vulnerability manifests during Unicode conversion processes when handling input parameters, creating a pathway for malicious code execution. The flaw is particularly concerning because it operates in a context-dependent manner, meaning that exploitation requires specific conditions to be met, but once triggered, it can lead to complete system compromise.
The technical implementation of this vulnerability stems from inadequate input validation within the iisfunc extension functions. When the iis_getservicestate function processes a long string in its first argument, particularly within the ServiceId parameter, the extension fails to properly validate the input length before performing memory operations. This allows attackers to overflow the allocated buffer space and overwrite adjacent memory locations. The vulnerability affects multiple functions including fnStartService, fnGetServiceState, fnStopService, and potentially others within the same extension, demonstrating a systemic flaw in how the extension handles parameter validation. The buffer overflow occurs during Unicode conversion processes, which adds complexity to the exploitation vector and makes the vulnerability more difficult to detect through standard security scanning tools.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with potential access to critical system resources and services. When successfully exploited, the buffer overflow allows context-dependent attackers to execute arbitrary code with the privileges of the web server process, which typically runs with elevated permissions on IIS servers. This can result in complete system compromise, data theft, service disruption, and potential lateral movement within network environments. The vulnerability is particularly dangerous in web server environments where PHP applications interact with IIS services, as it can be exploited through web-based attacks without requiring direct system access. The context-dependent nature of the vulnerability means that attackers must carefully craft their payloads to ensure successful exploitation, but the potential consequences make it a high-priority target for attackers.
Mitigation strategies for this vulnerability require immediate action from system administrators and developers. The most effective approach is to upgrade to PHP versions 5.2.1 or later where this vulnerability has been addressed through proper input validation and buffer management. Organizations should also implement proper input sanitization measures within their applications to prevent malicious input from reaching the vulnerable extension functions. Network-based mitigations such as web application firewalls can provide additional protection by filtering suspicious input patterns that might trigger the buffer overflow. Security monitoring should be enhanced to detect unusual patterns in IIS service interactions that could indicate exploitation attempts. The vulnerability aligns with CWE-121, which describes buffer overflow conditions where insufficient boundary checks allow memory access beyond allocated buffers, and it maps to ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would enable attackers to execute arbitrary commands through the compromised web server. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in other PHP extensions and components within the web server environment.