CVE-2007-5307 in ELSEIF CMS
Summary
by MITRE
ELSEIF CMS Beta 0.6 does not properly unset variables when the input data includes a numeric parameter with a value matching an alphanumeric parameter s hash value, which allows remote attackers to execute arbitrary PHP code by uploading a .php file via externe/swfupload/upload.php. NOTE: it could be argued that this vulnerability is due to a bug in the unset PHP command (CVE-2006-3017) and the proper fix should be in PHP; if so, then this should not be treated as a vulnerability in ELSEIF CMS.
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Analysis
by VulDB Data Team • 08/18/2025
The vulnerability described in CVE-2007-5307 affects the ELSEIF CMS Beta 0.6 content management system and represents a critical security flaw that stems from improper variable handling during input validation processes. This issue specifically manifests when the application processes numeric parameters that match the hash values of alphanumeric parameters, creating a condition where variables fail to be properly unset. The vulnerability exists within the application's file upload functionality, particularly in the externe/swfupload/upload.php component, which serves as an entry point for attackers to exploit the underlying flaw.
The technical mechanism behind this vulnerability involves PHP's variable handling and the unset function's behavior when processing certain parameter types. When numeric input data matches the hash value of an alphanumeric parameter, the unset operation fails to properly remove the variable from memory, leaving potentially malicious code in the execution environment. This creates a scenario where attackers can manipulate the application's variable scope to achieve unintended code execution. The flaw essentially allows for a form of variable injection or contamination where the expected behavior of variable cleanup is bypassed, enabling arbitrary PHP code execution within the context of the web server.
The operational impact of this vulnerability is severe as it provides remote attackers with complete control over the affected system. Attackers can upload malicious PHP files through the vulnerable upload.php endpoint and execute arbitrary code with the privileges of the web server process. This compromise can lead to full system takeover, data exfiltration, and persistence mechanisms being established. The vulnerability is particularly dangerous because it requires minimal user interaction beyond the initial upload, and the exploitation chain is relatively straightforward. The attack surface is further expanded by the fact that this vulnerability exists in the file upload functionality, which is often a common target for attackers seeking to establish persistent access to web applications.
This vulnerability aligns with CWE-128, which describes "Unsigned to Signed Conversion Error," and relates to improper handling of variable scope and cleanup operations. The issue demonstrates characteristics consistent with CWE-254, "Security Features Disabled or Ineffective," as the application fails to properly implement security measures for variable management during input processing. From an ATT&CK framework perspective, this vulnerability maps to T1190 "Exploit Public-Facing Application" and T1059.007 "Command and Scripting Interpreter: PHP" as it enables attackers to exploit a web application and execute malicious PHP code. The vulnerability also connects to T1078 "Valid Accounts" through potential privilege escalation scenarios where attackers can leverage the code execution capabilities to gain deeper system access.
The recommended mitigation strategy involves applying the appropriate PHP patch that addresses the underlying unset function behavior referenced in CVE-2006-3017, which is considered the root cause of this vulnerability. Organizations should implement proper input validation and sanitization procedures that prevent numeric and alphanumeric parameter conflicts in variable handling. Additionally, the upload functionality should be secured with proper file type validation, content verification, and access controls. The application should be updated to a newer version of ELSEIF CMS that addresses this specific vulnerability, as the beta 0.6 version is inherently unstable and lacks proper security hardening. Network segmentation and monitoring should be implemented to detect unauthorized file uploads and potential exploitation attempts, while regular security audits should verify that similar variable handling issues do not exist in other parts of the application.