Overview
CVE-2025-65838 identifies a path traversal vulnerability found in PublicCMS V5.202506.b. This vulnerability, present in the doUploadSitefile method, allows an attacker to potentially write files to arbitrary locations on the server, leading to various security risks. This article provides a detailed analysis of the vulnerability, its potential impact, and recommended mitigation strategies.
Technical Details
The vulnerability stems from insufficient sanitization of user-supplied input related to file paths during the upload process. Specifically, the doUploadSitefile method in PublicCMS V5.202506.b does not properly validate the destination path, allowing an attacker to inject directory traversal sequences (e.g., ../) into the file path. This allows the attacker to bypass intended directory restrictions and potentially upload files to locations outside of the designated upload directory.
An attacker can exploit this vulnerability by crafting a malicious request that includes a file path containing path traversal sequences. When the server processes this request, it may write the uploaded file to the attacker-specified location. This could overwrite critical system files or introduce malicious code into the system.
CVSS Analysis
Currently, the National Vulnerability Database (NVD) has not assigned a CVSS score to CVE-2025-65838. This may be due to the vulnerability being recently reported or under review. The severity is also listed as N/A. However, given the nature of path traversal vulnerabilities and their potential for leading to remote code execution (RCE), a high severity rating is anticipated upon CVSS scoring. We will update this section as soon as official scores are available. A successful exploit could lead to complete system compromise.
Possible Impact
The potential impact of CVE-2025-65838 is significant. A successful exploit could allow an attacker to:
- Overwrite critical system files: Leading to system instability or denial of service.
- Upload malicious code: Including web shells or other backdoors, enabling remote code execution and complete system compromise.
- Gain unauthorized access: To sensitive data stored on the server.
- Deface the website: By overwriting web content.
Mitigation and Patch Steps
To mitigate the risk of CVE-2025-65838, the following steps are recommended:
- Upgrade PublicCMS: Check the PublicCMS project website (https://github.com/sanluan/PublicCMS) for a patched version of PublicCMS that addresses this vulnerability. Apply the update as soon as it is available.
- Input Validation: Implement robust input validation on the server-side to sanitize file paths before they are used in file operations. Specifically, reject any file paths containing directory traversal sequences (
../). - Principle of Least Privilege: Ensure that the web server process runs with the minimum necessary privileges to perform its functions. This limits the potential impact of a successful exploit.
- Web Application Firewall (WAF): Deploy a WAF and configure it to block requests containing path traversal attempts. This can provide an additional layer of protection against exploitation.
- Regular Security Audits: Conduct regular security audits of your PublicCMS installation to identify and address potential vulnerabilities.
