CVE-2023-28699 in FANTSY
Summary
by MITRE • 06/02/2023
Wade Graphic Design FANTSY has a vulnerability of insufficient filtering for file type in its file update function. An authenticated remote attacker with general user privilege can exploit this vulnerability to upload a PHP file containing a webshell to perform arbitrary system operation or disrupt service.
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Analysis
by VulDB Data Team • 12/07/2025
The vulnerability identified as CVE-2023-28699 affects Wade Graphic Design FANTSY software, specifically targeting its file update functionality. This represents a critical security flaw that undermines the application's file validation mechanisms and exposes the system to remote code execution risks. The vulnerability stems from inadequate input filtering and validation processes that fail to properly verify the file types being uploaded through the application's update feature.
The technical implementation of this vulnerability resides in the file upload handler where the application does not adequately validate file extensions or content types before processing uploaded files. This insufficient filtering allows an authenticated attacker with standard user privileges to bypass security controls and upload malicious PHP files containing webshell code. The flaw essentially creates a pathway for attackers to execute arbitrary commands on the target system through the web server, as the application fails to distinguish between legitimate and malicious file types during the upload process.
From an operational impact perspective, this vulnerability enables attackers to gain persistent access to the compromised system and execute commands with the privileges of the web server process. The ability to upload PHP webshells provides attackers with a powerful foothold for further exploitation, including data exfiltration, system reconnaissance, and potential lateral movement within the network. The vulnerability's remote exploitability means that attackers can leverage this weakness without requiring physical access to the system, making it particularly dangerous for web-facing applications.
The security implications extend beyond simple privilege escalation as this vulnerability can be exploited to establish backdoors, maintain persistence, and conduct prolonged attacks against the affected system. Attackers can use the uploaded webshell to perform operations such as file manipulation, process management, and system information gathering. This vulnerability aligns with CWE-434 which addresses insecure file upload vulnerabilities, and maps to ATT&CK technique T1190 for Exploit Public-Facing Application, highlighting the threat landscape that this vulnerability exposes organizations to.
Organizations should implement immediate mitigations including strict file type validation, content type checking, and proper file extension filtering to prevent unauthorized uploads. The recommended approach involves implementing a whitelist of allowed file extensions, validating file content through multiple verification methods, and ensuring that uploaded files are stored outside the web root directory. Additionally, implementing proper access controls and monitoring for suspicious file upload activities can help detect and prevent exploitation attempts. Regular security audits and vulnerability assessments should be conducted to identify similar weaknesses in other application components, as this type of vulnerability often indicates broader security gaps in the application's defense mechanisms.