CVE-2025-3956: Xxyopen Novel-cloud SQL Injection Flaw

CVE-2025-3956 Overview

A critical SQL injection vulnerability has been discovered in xxyopen novel-cloud version 1.4.0. This vulnerability affects the RestResp function within the BookInfoMapper.xml file located at novel-cloud-master/novel-book/novel-book-service/src/main/resources/mapper/BookInfoMapper.xml. The flaw allows attackers to manipulate SQL queries through improper input handling, potentially enabling unauthorized access to the underlying database.

Critical Impact
This SQL injection vulnerability can be exploited remotely by authenticated attackers to read, modify, or delete database contents, potentially compromising the confidentiality, integrity, and availability of the novel-cloud application and its data.

Affected Products

xxyopen novel-cloud version 1.4.0

Discovery Timeline

2025-04-27 - CVE-2025-3956 published to NVD
2025-05-12 - Last updated in NVD database

Technical Details for CVE-2025-3956

Vulnerability Analysis

This SQL injection vulnerability exists in the MyBatis mapper XML configuration file for the novel-cloud application. The BookInfoMapper.xml file contains improperly constructed SQL queries that fail to adequately sanitize user-controlled input before incorporating it into database queries. When the RestResp function processes requests, malicious SQL fragments can be injected through manipulated parameters, allowing attackers to execute arbitrary SQL commands against the backend database.

The vulnerability is network-accessible, meaning attackers can exploit it remotely without physical access to the target system. While authentication is required (low privileges), the attack complexity is low, making exploitation relatively straightforward once an attacker gains initial access to the application.

Root Cause

The root cause of this vulnerability (CWE-89: SQL Injection, CWE-74: Injection) stems from insufficient input validation and improper parameterization in the MyBatis mapper configuration. The BookInfoMapper.xml file uses string concatenation or improper placeholder syntax (${} instead of #{} in MyBatis) when constructing SQL queries, allowing user-supplied data to be interpreted as SQL code rather than data values.

Attack Vector

The attack vector is network-based, enabling remote exploitation. An attacker with low-level privileges can craft malicious HTTP requests containing SQL injection payloads targeting the vulnerable mapper endpoint. The injected SQL code is then executed by the database server with the privileges of the application's database connection.

The exploitation technique involves sending specially crafted requests to the novel-cloud API endpoints that utilize the BookInfoMapper.xml for data retrieval. By manipulating input parameters, attackers can inject SQL statements that bypass authentication checks, extract sensitive data, modify records, or potentially execute administrative database commands.

Technical details and proof-of-concept information have been documented in the GitHub PoC Repository. Additional vulnerability intelligence is available through VulDB #306292.

Detection Methods for CVE-2025-3956

Indicators of Compromise

Unusual SQL error messages in application logs indicating malformed queries or syntax errors
Database logs showing unexpected queries containing SQL keywords like UNION, SELECT, OR 1=1, or comment sequences (--, /**/)
Abnormal patterns in web access logs targeting endpoints associated with the book information service
Unexpected data modifications or unauthorized data access in the database audit logs

Detection Strategies

Implement Web Application Firewall (WAF) rules to detect and block common SQL injection patterns targeting the novel-cloud application
Enable detailed logging on the database server to capture and analyze all queries executed by the application
Deploy network intrusion detection systems (IDS) with signatures for SQL injection attack patterns
Monitor application response times and error rates for anomalies that may indicate exploitation attempts

Monitoring Recommendations

Configure SIEM alerts for SQL injection patterns in web server and application logs
Establish baseline behavior for database query patterns and alert on deviations
Monitor for authentication anomalies following potential SQL injection attempts
Review database user activity logs for privilege escalation or unauthorized administrative commands

How to Mitigate CVE-2025-3956

Immediate Actions Required

Restrict network access to the novel-cloud application to trusted IP addresses only
Implement input validation and filtering at the application layer as a temporary measure
Enable WAF rules to block SQL injection attempts targeting the affected endpoints
Consider temporarily disabling the affected book information functionality if feasible

Patch Information

The vendor (xxyopen) was contacted regarding this vulnerability but did not respond. As of the last modification date (2025-05-12), no official patch has been released for novel-cloud version 1.4.0. Organizations using this software should monitor the official repository for updates and consider implementing the workarounds described below.

For the latest vulnerability details, refer to VulDB CTI ID #306292.

Workarounds

Migrate from vulnerable ${} syntax to properly parameterized #{} placeholders in the BookInfoMapper.xml file to prevent SQL injection
Implement prepared statements with parameter binding for all database queries in the affected mapper
Deploy a reverse proxy with SQL injection filtering capabilities in front of the application
Apply the principle of least privilege to the database user account used by the application, limiting permissions to only those strictly necessary

bash

# Example: Restrict database user permissions (MySQL)
# Revoke unnecessary privileges from the novel-cloud database user
REVOKE ALL PRIVILEGES ON novel_db.* FROM 'novel_user'@'%';
GRANT SELECT, INSERT, UPDATE ON novel_db.books TO 'novel_user'@'%';
GRANT SELECT ON novel_db.categories TO 'novel_user'@'%';
FLUSH PRIVILEGES;