CVE-2018-8944 in PHPOK
Summary
by MITRE
PHPOK 4.8.338 has an arbitrary file upload vulnerability.
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Analysis
by VulDB Data Team • 01/16/2020
The CVE-2018-8944 vulnerability represents a critical arbitrary file upload flaw in PHPOK version 4.8.338, which exposes systems to potential remote code execution and persistent compromise. This vulnerability stems from insufficient input validation and improper file type checking within the application's upload functionality, allowing malicious actors to bypass security controls and upload malicious files to the target system. The flaw exists in the web application's file handling mechanisms where user-supplied filenames and content are not adequately sanitized or restricted, creating an avenue for attackers to inject harmful code into the server environment.
The technical implementation of this vulnerability involves the application's failure to properly validate file extensions, MIME types, and content signatures during the upload process. Attackers can exploit this by crafting malicious files with extensions that appear legitimate but contain executable code or scripts that can be interpreted by the web server. The vulnerability typically manifests when users with upload privileges or unauthenticated attackers can manipulate the file upload interface to bypass security checks, potentially uploading files with extensions like .php, .asp, .jsp, or other server-side script formats that can execute commands on the target server. This flaw directly maps to CWE-434 which categorizes insecure file upload vulnerabilities, and aligns with ATT&CK technique T1190 for Exploit Public-Facing Application, as it allows adversaries to gain initial access through web application exploitation.
The operational impact of CVE-2018-8944 extends beyond simple unauthorized file uploads, as successful exploitation can lead to complete system compromise, data exfiltration, and persistent backdoor access. Once an attacker gains the ability to upload arbitrary files, they can deploy web shells, reverse shells, or other malicious payloads that maintain persistence on the compromised system. The vulnerability affects organizations using PHPOK 4.8.338 across various deployment scenarios including web hosting environments, content management systems, and enterprise applications that rely on this vulnerable software stack. The risk is particularly severe in environments where the web application runs with elevated privileges or where the upload directory has write permissions for the web server process, as this enables direct code execution without additional exploitation steps.
Mitigation strategies for CVE-2018-8944 require immediate remediation through software updates to the latest PHPOK versions that address the file upload validation issues. Organizations should implement comprehensive file validation mechanisms including strict extension filtering, MIME type verification, and content-based file analysis to prevent malicious uploads. Network-level protections such as web application firewalls should be configured to monitor and block suspicious upload patterns, while proper access controls and least privilege principles should be enforced to limit upload capabilities to authorized users only. The implementation of secure coding practices including input sanitization, proper file handling, and runtime file validation should be prioritized to prevent similar vulnerabilities in future development cycles. Additionally, regular security assessments and penetration testing should be conducted to identify and remediate similar weaknesses in the application's security posture, with security monitoring systems deployed to detect unauthorized file upload activities and potential exploitation attempts.