CVE-2025-3369: Xxyopen Novel-plus SQL Injection Flaw

CVE-2025-3369 Overview

A critical SQL injection vulnerability has been discovered in xxyopen Novel-Plus version 5.1.0. The vulnerability exists in the /novel/friendLink/list endpoint where improper handling of the sort parameter allows attackers to inject malicious SQL queries. This flaw enables remote attackers to manipulate database queries, potentially leading to unauthorized data access, data modification, or complete database compromise.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability to extract sensitive data, modify database contents, or potentially gain unauthorized access to the underlying system through the /novel/friendLink/list endpoint.

Affected Products

• xxyopen Novel-Plus version 5.1.0
• Novel-Plus deployments using the vulnerable /novel/friendLink/list endpoint

Discovery Timeline

• 2025-04-07 - CVE-2025-3369 published to NVD
• 2025-10-10 - Last updated in NVD database

Technical Details for CVE-2025-3369

Vulnerability Analysis

This SQL injection vulnerability in xxyopen Novel-Plus 5.1.0 stems from insufficient input validation and sanitization in the friend link listing functionality. The application fails to properly sanitize user-supplied input in the sort parameter before incorporating it into SQL queries. This allows attackers to break out of the intended query structure and execute arbitrary SQL commands against the backend database.

The vulnerability is remotely exploitable and requires low privileges to execute, making it accessible to authenticated users with minimal access. Once exploited, attackers can potentially read, modify, or delete data across the database, depending on the database user permissions configured for the application.

Root Cause

The root cause of CVE-2025-3369 is improper input validation (CWE-89: SQL Injection) combined with improper neutralization of special elements used in commands (CWE-74: Injection). The application directly incorporates user-controlled input from the sort parameter into database queries without proper parameterization or sanitization, allowing SQL metacharacters to be interpreted as part of the query structure rather than literal data.

Attack Vector

The attack is network-based and targets the /novel/friendLink/list endpoint. An authenticated attacker can craft malicious HTTP requests containing SQL injection payloads in the sort parameter. When the application processes these requests, the malicious SQL code is executed against the database, potentially allowing data extraction through techniques such as UNION-based injection, error-based injection, or blind SQL injection depending on the application's error handling behavior.

The vulnerability has been publicly disclosed with a proof-of-concept available in a GitHub PoC Repository, which security teams should review for detection signature development. Additional technical context is available through VulDB #303614.

Detection Methods for CVE-2025-3369

Indicators of Compromise

• Unusual or malformed requests to the /novel/friendLink/list endpoint containing SQL syntax in the sort parameter
• Database error messages appearing in application logs indicating SQL syntax errors
• Unexpected database query patterns or execution times suggesting injection attempts
• Access logs showing repeated requests with varying payloads to the vulnerable endpoint

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in the sort parameter
• Deploy database activity monitoring to identify anomalous query patterns or unauthorized data access attempts
• Configure application-level logging to capture and alert on requests containing SQL metacharacters
• Use intrusion detection systems (IDS) with signatures for SQL injection attack patterns targeting this specific endpoint

Monitoring Recommendations

• Monitor web server access logs for requests to /novel/friendLink/list containing suspicious characters such as single quotes, UNION statements, or comment sequences
• Enable database query logging to track unusual query patterns that may indicate exploitation
• Set up alerting for multiple failed authentication attempts followed by successful exploitation patterns
• Review application error logs for SQL-related exceptions that may indicate injection attempts

How to Mitigate CVE-2025-3369

Immediate Actions Required

• Restrict access to the /novel/friendLink/list endpoint until a patch is applied
• Implement input validation and sanitization for the sort parameter at the application layer
• Deploy WAF rules to block common SQL injection patterns targeting this endpoint
• Review database user permissions to ensure the application uses least-privilege access

Patch Information

As of the last update, no official vendor patch has been confirmed for this vulnerability. Organizations using Novel-Plus 5.1.0 should monitor the vendor's official channels for security updates. In the absence of a patch, implementing the workarounds below is critical to reduce exposure.

Workarounds

• Implement parameterized queries or prepared statements for all database operations involving the sort parameter
• Add server-side input validation to whitelist acceptable sort values and reject any input containing SQL metacharacters
• Consider disabling or removing the friend link functionality if it is not business-critical until a proper fix is available
• Deploy a reverse proxy or WAF to inspect and filter incoming requests to the vulnerable endpoint

# Example WAF rule to block SQL injection attempts on the vulnerable endpoint
# This is a general mitigation approach - adjust for your specific WAF solution
# Block requests containing SQL injection patterns in the sort parameter
SecRule ARGS:sort "@detectSQLi" \
    "id:100001,\
    phase:2,\
    deny,\
    status:403,\
    msg:'SQL Injection attempt detected in sort parameter',\
    logdata:'Matched Data: %{MATCHED_VAR}'"