CVE-2025-13816: Mogublog Path Traversal Vulnerability

CVE-2025-13816 Overview

A path traversal vulnerability has been identified in moxi159753 Mogu Blog v2 through version 5.2. The vulnerability exists in the FileOperation.unzip function within the /networkDisk/unzipFile endpoint of the ZIP File Handler component. An attacker can manipulate the fileUrl argument to perform path traversal attacks, potentially allowing unauthorized access to files outside the intended directory structure. The attack can be launched remotely, and a public exploit has been disclosed. The vendor was contacted regarding this vulnerability but did not respond.

Critical Impact

Remote attackers with low privileges can exploit this path traversal vulnerability to read or write files outside the intended directory, potentially leading to sensitive data exposure or arbitrary file manipulation on the server.

Affected Products

• Mogu Blog v2 up to version 5.2
• mogublog_project mogublog (all versions up to 5.2)

Discovery Timeline

• 2025-12-01 - CVE-2025-13816 published to NVD
• 2025-12-03 - Last updated in NVD database

Technical Details for CVE-2025-13816

Vulnerability Analysis

CVE-2025-13816 is a path traversal vulnerability (CWE-22) affecting the ZIP file extraction functionality in Mogu Blog v2. The vulnerability has been assigned a CVSS 4.0 score of 5.3 (MEDIUM severity) with the vector string CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

The EPSS (Exploit Prediction Scoring System) indicates a probability of 0.111% with a percentile of 30.31%, suggesting a relatively low but non-trivial likelihood of exploitation in the wild.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the FileOperation.unzip function. When processing ZIP files via the /networkDisk/unzipFile endpoint, the application fails to properly sanitize the fileUrl parameter. This allows attackers to include directory traversal sequences (such as ../) in file paths within ZIP archives, enabling them to extract files to arbitrary locations on the server file system. This type of vulnerability is commonly known as "Zip Slip."

Attack Vector

The attack can be executed remotely over the network with low attack complexity. An authenticated attacker with low privileges can craft a malicious ZIP archive containing files with path traversal sequences in their names. When this archive is processed by the vulnerable unzipFile endpoint, the files are extracted outside the intended extraction directory.

The exploitation mechanism involves creating a ZIP archive where the archived file paths contain sequences like ../../etc/passwd or ../../../webapp/webshell.jsp. When extracted, these files are written to locations outside the designated extraction folder, potentially overwriting critical system files or placing malicious files in web-accessible directories.

For detailed technical information and proof-of-concept, refer to the publicly available exploit report at https://github.com/Xzzz111/exps/blob/main/archives/mogu_blog_v2-zip_slip-1/report.md.

Detection Methods for CVE-2025-13816

Indicators of Compromise

• Unusual file creation or modification events outside the expected upload/extraction directories
• HTTP requests to /networkDisk/unzipFile containing suspicious file paths or encoded traversal sequences
• Web server logs showing access to the unzipFile endpoint with unusual fileUrl parameter values
• Presence of unexpected files in web root or system directories following ZIP file processing
• Error logs indicating file write operations to paths outside the application directory

Detection Strategies

Organizations should implement multiple layers of detection to identify potential exploitation attempts:

Log Analysis: Monitor application and web server logs for requests to the /networkDisk/unzipFile endpoint. Look for patterns containing ../, URL-encoded traversal sequences (%2e%2e%2f), or unusual file extensions in the fileUrl parameter.

File Integrity Monitoring: Deploy file integrity monitoring solutions to detect unauthorized file creation or modification in sensitive directories such as web roots, configuration directories, and system paths.

Network Traffic Analysis: Inspect HTTP traffic for POST requests to the vulnerable endpoint containing ZIP files with suspicious internal file paths. SentinelOne Singularity XDR can provide behavioral detection capabilities to identify anomalous file system activities associated with path traversal attacks.

Monitoring Recommendations

Implement real-time monitoring on the following:

• File system activities in and around the Mogu Blog installation directory
• HTTP request patterns to the /networkDisk/unzipFile endpoint
• User authentication events followed by ZIP file upload activities
• Any file writes outside designated upload directories
• Process execution following ZIP extraction operations

How to Mitigate CVE-2025-13816

Immediate Actions Required

• Restrict access to the /networkDisk/unzipFile endpoint to only trusted administrators
• Implement web application firewall (WAF) rules to block requests containing path traversal sequences
• Review file system permissions to limit the impact of potential exploitation
• Audit existing files on the server for any signs of compromise
• Consider temporarily disabling the ZIP file extraction functionality until a patch is available

Patch Information

As of the last modification date (2025-12-03), no official patch has been released by the vendor. The vendor was contacted regarding this vulnerability but did not respond. Users are strongly advised to implement the workarounds described below and monitor for any future security updates from the Mogu Blog project.

Workarounds

Since no official patch is available, organizations should implement the following defensive measures:

Input Validation: If access to the source code is available, implement proper path canonicalization and validation in the FileOperation.unzip function. Ensure extracted file paths are validated to remain within the intended extraction directory.

Access Control: Restrict network access to the vulnerable endpoint using firewall rules or reverse proxy configurations:

# Example nginx configuration to restrict access to the vulnerable endpoint
location /networkDisk/unzipFile {
    # Deny all external access
    deny all;
    # Or restrict to trusted IPs only
    # allow 192.168.1.0/24;
    # deny all;
}

Application Isolation: Consider running the Mogu Blog application in a containerized environment with limited file system access to reduce the potential impact of exploitation. SentinelOne's cloud workload protection can provide runtime security for containerized deployments.