Mogu Blog v2 Vulnerable to Path Traversal: CVE-2025-13816 Exposes Your Server

Overview

A medium severity security vulnerability, identified as CVE-2025-13816, has been discovered in Mogu Blog v2 up to version 5.2. This vulnerability stems from a path traversal flaw within the ZIP file handling functionality. An attacker can exploit this flaw to potentially read or write arbitrary files on the server, leading to significant security risks.

The vulnerability is located within the FileOperation.unzip function of the /networkDisk/unzipFile component. Successful exploitation requires no authentication and can be performed remotely.

Technical Details

The root cause of CVE-2025-13816 is insufficient sanitization of the fileUrl argument passed to the FileOperation.unzip function. This lack of proper validation allows an attacker to craft a malicious ZIP archive containing entries with path traversal sequences (e.g., ../). When the server attempts to extract the archive, these sequences allow the attacker to write files outside the intended extraction directory.

This is a classic Zip Slip vulnerability. The attacker creates a ZIP archive where the filenames contain directory traversal strings, allowing them to write outside the intended target directory.

CVSS Analysis

The Common Vulnerability Scoring System (CVSS) assigns CVE-2025-13816 a score of 6.3, indicating a MEDIUM severity vulnerability. This score reflects the remote exploitability and the potential impact on confidentiality and integrity. The CVSS vector string would likely include factors related to network attack vector and potential for arbitrary file writing.

Possible Impact

Successful exploitation of this vulnerability could have severe consequences, including:

• Arbitrary File Read: An attacker could read sensitive configuration files, database credentials, or source code.
• Arbitrary File Write: An attacker could overwrite existing files, inject malicious code into web server directories (leading to remote code execution), or create backdoors for persistent access.
• Denial of Service (DoS): By overwriting critical system files, an attacker could disrupt the availability of the application.
• Complete System Compromise: In a worst-case scenario, an attacker could gain full control of the affected server.

Mitigation and Patch Steps

Unfortunately, the vendor has not responded to responsible disclosure attempts. Therefore, the following mitigation steps are recommended:

• Upgrade: If a patch is released in the future, immediately upgrade to the latest version of Mogu Blog v2. This is the ideal solution. Check the Mogu Blog website frequently for updates.
• Input Validation: Implement strict validation of the fileUrl parameter before passing it to the FileOperation.unzip function. Sanitize the input to prevent path traversal sequences.
• Safe Archive Extraction: Use a secure archive extraction library that prevents path traversal vulnerabilities. Ensure the library is configured to properly handle potentially malicious archive entries.
• Chroot Environment: Consider running the archive extraction process within a chroot environment to limit the attacker’s ability to access the rest of the file system.
• Web Application Firewall (WAF): Deploy a WAF with rules to detect and block path traversal attempts.

References

GitHub Exploit Report (Proof of Concept)
VulDB Entry: Correlation ID 333825
VulDB Entry: Vulnerability ID 333825