CVE-2006-5918 in PHP Rapid Kill
Summary
by MITRE
Unrestricted file upload vulnerability in RapidKill (aka PHP Rapid Kill) 5.7 Pro, and certain other versions, allows remote attackers to upload and execute arbitrary PHP scripts via the "Link to Download" field. NOTE: it is possible that the field value is restricted to files on specific public web sites.
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Analysis
by VulDB Data Team • 04/27/2026
The CVE-2006-5918 vulnerability represents a critical unrestricted file upload flaw in RapidKill (also known as PHP Rapid Kill) version 5.7 Pro and related versions. This vulnerability stems from inadequate input validation and sanitization mechanisms within the application's file upload functionality, specifically targeting the "Link to Download" field. The flaw allows remote attackers to bypass normal file upload restrictions and execute arbitrary PHP code on the target server, fundamentally compromising the system's integrity and security posture.
This vulnerability directly maps to CWE-434, which describes the weakness of unrestricted upload of file with dangerous type. The technical implementation flaw occurs when the application fails to properly validate file extensions, content types, or file contents before processing uploads. Attackers can exploit this by crafting malicious PHP scripts and uploading them through the vulnerable field, which then gets executed on the web server. The vulnerability is particularly dangerous because it allows for remote code execution, enabling attackers to gain full control over the affected system.
The operational impact of CVE-2006-5918 is severe and multifaceted. Successful exploitation can result in complete system compromise, data exfiltration, and the establishment of persistent backdoors. Attackers can upload web shells, reverse shells, or other malicious payloads that provide them with unauthorized access to the server environment. The vulnerability also poses risks to the broader network infrastructure as attackers can use compromised systems as launch points for lateral movement and further attacks. Additionally, the impact extends to data confidentiality, integrity, and availability, as attackers can modify, delete, or corrupt system files and databases.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization measures. The most effective approach involves implementing strict file type validation, rejecting executable file extensions, and implementing proper content type checking. Organizations should also deploy web application firewalls to monitor and filter suspicious upload attempts, implement proper access controls, and ensure that all file upload functionalities are properly secured with authentication and authorization checks. The principle of least privilege should be applied to file upload directories, and proper file permissions should be configured to prevent execution of uploaded files. Regular security assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities, while keeping all software components updated to prevent exploitation of known vulnerabilities. This vulnerability aligns with ATT&CK technique T1190, which covers the use of legitimate credentials and file upload capabilities for persistence and privilege escalation.