CVE-2025-13813: Mogublog Auth Bypass Vulnerability

CVE-2025-13813 Overview

CVE-2025-13813 is a Missing Authorization vulnerability identified in moxi159753 Mogu Blog v2 up to version 5.2. This security flaw affects the Storage Management Endpoint (/storage/) component, where improper access control allows attackers to perform unauthorized operations. The vulnerability can be exploited remotely over the network, though the attack complexity is rated as high.

Critical Impact

Attackers can exploit this broken access control vulnerability to perform unauthorized actions on the storage management functionality, potentially leading to unauthorized data access, modification, or deletion. An exploit is publicly available.

Affected Products

• Mogublog_project Mogublog versions up to 5.2
• Mogu Blog v2 Storage Management Endpoint (/storage/)
• Systems running vulnerable Mogu Blog deployments exposed to network access

Discovery Timeline

• 2025-12-01 - CVE-2025-13813 published to NVD
• 2025-12-03 - Last updated in NVD database

Technical Details for CVE-2025-13813

Vulnerability Analysis

This vulnerability is classified as CWE-862 (Missing Authorization), a type of Broken Access Control flaw. The Storage Management Endpoint at /storage/ fails to properly verify that authenticated users have the necessary permissions before processing requests. This allows unauthorized users to access and potentially manipulate storage-related functionality that should be restricted to administrators or privileged users.

The vulnerability has been assigned a CVSS 4.0 score of 6.3 (Medium). The CVSS vector CVSS:4.0/AV:N/AC:H/AT:N/PR:N/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 indicates:

• Attack Vector: Network-based exploitation
• Attack Complexity: High
• Privileges Required: None
• User Interaction: None
• Impact: Low confidentiality, integrity, and availability impact

The EPSS (Exploit Prediction Scoring System) score is 0.042% with a percentile ranking of 12.519, suggesting relatively low exploitation probability in the wild despite the public exploit availability.

Root Cause

The root cause of CVE-2025-13813 lies in the absence of proper authorization checks in the Storage Management Endpoint. The application fails to validate whether the requesting user has appropriate permissions to access storage management functions. This design flaw allows any remote attacker who can reach the endpoint to bypass access controls and interact with the storage component without authentication or with insufficient authorization verification.

Attack Vector

The attack is initiated remotely over the network by sending crafted requests to the /storage/ endpoint. While the attack complexity is rated as high and exploitability is assessed as difficult, a proof-of-concept exploit has been publicly disclosed.

The vulnerability exploitation involves sending HTTP requests to the /storage/ endpoint without proper authorization credentials. Due to the missing authorization checks, the server processes these requests as if they came from an authorized user. Technical details of the exploitation methodology can be found in the publicly available exploit report.

Detection Methods for CVE-2025-13813

Indicators of Compromise

• Unusual or unexpected access patterns to the /storage/ endpoint from unauthorized IP addresses
• HTTP requests to storage management functions lacking valid session tokens or authentication headers
• Log entries showing storage operations performed by non-administrative users or anonymous sessions

Detection Strategies

Organizations can implement the following detection mechanisms to identify potential exploitation attempts:

1. Web Application Firewall (WAF) Rules: Configure rules to monitor and alert on direct access attempts to /storage/ endpoints, especially from unauthenticated sessions or unexpected source IPs.

2. Log Analysis: Review web server access logs for patterns of requests to /storage/ that lack appropriate authentication tokens or originate from suspicious sources.

3. Network Monitoring: Monitor network traffic for anomalous patterns targeting the Mogu Blog application, particularly focusing on storage-related API calls.

4. SentinelOne Singularity Platform: Leverage SentinelOne's behavioral AI to detect unauthorized access patterns and suspicious activity targeting web applications. The platform can identify exploitation attempts through endpoint telemetry and network behavior analysis.

Monitoring Recommendations

Implement continuous monitoring of the Mogu Blog application with focus on:

• Real-time alerting for access to administrative endpoints without proper authorization
• Audit logging of all storage management operations with user identity correlation
• Periodic security assessments to verify authorization controls are functioning correctly
• Integration with SIEM solutions to correlate access patterns across the application stack

How to Mitigate CVE-2025-13813

Immediate Actions Required

• Restrict network access to the /storage/ endpoint using firewall rules or network segmentation
• Implement authentication and authorization middleware to validate all requests to storage management functions
• Review application logs for evidence of unauthorized access attempts
• Consider temporarily disabling the Storage Management feature if not critical to operations

Patch Information

The vendor (moxi159753/Mogu Blog project) was contacted about this vulnerability but did not respond. As of the last NVD update on 2025-12-03, no official patch has been released. Organizations should monitor the Mogu Blog GitHub repository for security updates.

In the absence of a vendor patch, organizations should:

1. Apply defense-in-depth measures to protect the vulnerable endpoint
2. Consider implementing a custom patch or fork if source code access is available
3. Evaluate migration to alternative blog platforms with better security support

Workarounds

Since no official patch is available, organizations should implement the following compensating controls:

# Example: Nginx configuration to restrict access to /storage/ endpoint
# Add to your Nginx server block configuration

location /storage/ {
    # Allow only from trusted internal networks
    allow 10.0.0.0/8;
    allow 192.168.0.0/16;
    deny all;
    
    # Require authentication
    auth_basic "Restricted Access";
    auth_basic_user_file /etc/nginx/.htpasswd;
    
    # Pass to backend if authorized
    proxy_pass http://mogu_blog_backend;
}

Additional workarounds include:

• Deploy a reverse proxy with authentication requirements for administrative endpoints
• Implement IP-based access control lists to limit who can reach the storage management functionality
• Use a Web Application Firewall (WAF) to enforce authorization policies at the network layer
• Enable comprehensive logging and integrate with security monitoring tools for rapid incident detection