Overview
A significant security vulnerability, identified as CVE-2025-63918, has been discovered in PDFPatcher. This vulnerability allows attackers to perform directory traversal attacks due to insufficient validation of user-supplied file paths. This flaw enables malicious actors to upload arbitrary files to arbitrary locations on the system where PDFPatcher is installed, potentially leading to severe consequences.
Technical Details
The root cause of this vulnerability lies in the PDFPatcher executable’s failure to properly sanitize or validate file paths provided by the user. Specifically, the application does not adequately prevent the use of “..” sequences or other path manipulation techniques when handling file upload or export functionalities. This allows an attacker to craft a malicious request that bypasses intended security restrictions, enabling them to write files outside of the designated directories.
The vulnerability is related to image export functionality as detailed in the following research.
CVSS Analysis
Currently, the CVSS score for CVE-2025-63918 is listed as N/A. This indicates that the vulnerability’s severity and impact have not yet been formally assessed using the CVSS framework. However, the potential for arbitrary file upload suggests a high level of risk, as successful exploitation could lead to code execution, data compromise, or system takeover. A detailed CVSS analysis will be provided once available.
Possible Impact
The exploitation of CVE-2025-63918 can have severe consequences, including:
- Arbitrary Code Execution: Attackers can upload executable files to the system and execute them, gaining complete control.
- Data Compromise: Sensitive data can be accessed, modified, or deleted by malicious actors.
- System Takeover: Successful exploitation could lead to full system compromise, allowing attackers to control the affected machine.
- Denial of Service: Attackers might be able to overwrite critical system files, leading to a denial-of-service condition.
Mitigation and Patch Steps
To mitigate the risk associated with CVE-2025-63918, the following steps are recommended:
- Apply the Patch: Check the PDFPatcher website and GitHub repository for official patches or updates released by the vendor and apply them immediately.
- Input Validation: If a patch is not yet available, implement strict input validation and sanitization of all user-supplied file paths. Ensure that “..” sequences and other path manipulation techniques are blocked.
- Least Privilege: Run PDFPatcher with the least necessary privileges to minimize the impact of potential exploitation.
- Web Application Firewall (WAF): If PDFPatcher is used in a web-based context, configure a Web Application Firewall (WAF) to detect and block malicious requests attempting to exploit this vulnerability.
- Monitor System Activity: Closely monitor system logs for any suspicious activity, such as unexpected file creations or modifications.
