CVE-2025-60735 Overview
CVE-2025-60735 is an arbitrary file upload vulnerability affecting PerfreeBlog version 4.0.11. The flaw resides in the installPlugin function, which fails to validate uploaded plugin files. Authenticated attackers can abuse this endpoint to upload malicious files to the server. The issue is tracked under CWE-434: Unrestricted Upload of File with Dangerous Type. Successful exploitation can lead to arbitrary code execution within the context of the web application. The vulnerability is reachable over the network and requires only low privileges, increasing its practical impact in deployments where blog accounts are widely provisioned.
Critical Impact
Authenticated attackers can upload arbitrary files through the installPlugin function in PerfreeBlog 4.0.11, leading to code execution on the underlying server.
Affected Products
- PerfreeBlog 4.0.11
- Perfree PerfreeBlog (CPE: cpe:2.3:a:perfree:perfreeblog:4.0.11)
- Self-hosted PerfreeBlog deployments running the affected plugin installation endpoint
Discovery Timeline
- 2025-10-24 - CVE-2025-60735 published to NVD
- 2025-10-27 - Last updated in NVD database
Technical Details for CVE-2025-60735
Vulnerability Analysis
The vulnerability exists in PerfreeBlog's plugin installation workflow. PerfreeBlog supports extensibility through user-installable plugins, and the installPlugin function accepts archive files that are extracted and registered on the server. In version 4.0.11, this function does not enforce sufficient validation of the uploaded file type, content, or extracted contents.
An attacker who holds a valid low-privileged session can submit a crafted plugin archive containing executable server-side code. Once the archive is processed by installPlugin, the malicious payload is written to a location reachable by the application runtime. The attacker can then invoke the file to gain code execution within the PerfreeBlog process context.
Root Cause
The root cause is missing or insufficient validation of uploaded files in the plugin installation handler. The function does not restrict dangerous file extensions, does not verify MIME types against expected plugin formats, and does not sanitize archive entries before extraction. This category of weakness is classified under CWE-434.
Attack Vector
The attack vector is network-based and requires authentication. An attacker submits a POST request to the plugin installation endpoint with a malicious archive. After the server processes the archive, the attacker requests the uploaded resource directly to trigger execution. Detailed technical analysis is documented in the GitHub CVE Analysis on PerfreeBlog.
Detection Methods for CVE-2025-60735
Indicators of Compromise
- HTTP requests to the PerfreeBlog plugin installation endpoint containing archive uploads from non-administrative user sessions
- Unexpected files with executable extensions (.jsp, .jspx, .class, .sh) appearing inside the PerfreeBlog plugin directory
- New plugin directories created outside of scheduled administrative maintenance windows
- Outbound network connections originating from the PerfreeBlog Java process to unfamiliar hosts following a plugin installation event
Detection Strategies
- Monitor web server access logs for POST requests to the installPlugin route, correlating with the authenticated user identity and source IP
- Apply file integrity monitoring on the PerfreeBlog plugin and webroot directories to alert on unexpected file creation
- Inspect uploaded archives for entries with server-executable extensions before extraction completes
Monitoring Recommendations
- Forward PerfreeBlog application and web server logs to a centralized analytics platform and alert on plugin installation activity
- Track child process creation from the PerfreeBlog Java process to detect post-upload command execution
- Review authentication logs for low-privileged accounts performing administrative-style actions such as plugin installation
How to Mitigate CVE-2025-60735
Immediate Actions Required
- Restrict access to the PerfreeBlog administrative and plugin installation endpoints to trusted IP ranges using a reverse proxy or web application firewall
- Audit existing PerfreeBlog user accounts and revoke plugin installation privileges from non-administrative users
- Inspect the plugin directory for unauthorized files and remove any artifacts that were not installed by an administrator
Patch Information
No vendor advisory or fixed version is listed in the enriched data at the time of publication. Monitor the Perfree Official Website and the Perfree Blog project page for an updated release that addresses CVE-2025-60735.
Workarounds
- Disable the plugin installation feature on internet-exposed PerfreeBlog instances until a patched version is available
- Enforce strict allowlists for uploaded file extensions and validate archive contents before extraction at the reverse proxy layer
- Run the PerfreeBlog application under a least-privileged service account to limit the blast radius of code execution
- Place the application behind a web application firewall rule that blocks archive uploads to the plugin installation endpoint from non-administrative sessions
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
