CVE-2026-1120: Yonyou KSOA 9.0 SQL Injection Vulnerability

CVE-2026-1120 Overview

A SQL injection vulnerability has been identified in Yonyou KSOA 9.0, specifically affecting the /worksheet/del_work.jsp file within the HTTP GET Parameter Handler component. The vulnerability allows attackers to manipulate the ID parameter to inject malicious SQL queries, potentially compromising the integrity and confidentiality of the underlying database. This vulnerability can be exploited remotely without authentication, making it a significant security concern for organizations using this enterprise software.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability to extract sensitive data, modify database contents, or potentially gain further access to backend systems through unauthenticated HTTP GET requests.

Affected Products

• Yonyou KSOA 9.0

Discovery Timeline

• 2026-01-18 - CVE CVE-2026-1120 published to NVD
• 2026-01-18 - Last updated in NVD database

Technical Details for CVE-2026-1120

Vulnerability Analysis

This vulnerability is a classic SQL injection flaw (CWE-74: Injection) that occurs due to improper handling of user-supplied input in the ID parameter. When processing HTTP GET requests to the /worksheet/del_work.jsp endpoint, the application fails to properly sanitize or parameterize the input before incorporating it into SQL queries. This allows an attacker to craft malicious input that alters the intended SQL query structure, enabling unauthorized database operations.

The exploit has been publicly disclosed, increasing the risk of widespread exploitation. Despite early notification, the vendor has not responded to disclosure attempts, leaving users without an official patch or mitigation guidance.

Root Cause

The root cause of this vulnerability lies in the application's failure to implement proper input validation and parameterized queries when processing the ID parameter in the HTTP GET request handler. The del_work.jsp file directly incorporates user-supplied data into SQL statements without sanitization, allowing specially crafted input to escape the intended query context and execute arbitrary SQL commands.

Attack Vector

The attack can be initiated remotely over the network without requiring any authentication or user interaction. An attacker sends a crafted HTTP GET request to the vulnerable endpoint /worksheet/del_work.jsp with a malicious ID parameter value containing SQL injection payloads. The vulnerable application processes this input without proper validation, executing the injected SQL commands against the backend database.

The exploitation mechanism involves injecting SQL syntax through the ID parameter that breaks out of the intended query structure. Typical payloads may include UNION-based injection for data extraction, boolean-based blind injection for inferring database contents, or time-based blind injection when direct output is not available. For detailed technical analysis and proof-of-concept information, refer to the GitHub CVE Issue Discussion and VulDB #341712.

Detection Methods for CVE-2026-1120

Indicators of Compromise

• Unusual HTTP GET requests to /worksheet/del_work.jsp containing SQL syntax characters such as single quotes, semicolons, or SQL keywords in the ID parameter
• Database error messages in application logs indicating malformed SQL queries
• Unexpected database queries or data access patterns originating from the web application layer
• Evidence of data exfiltration or unauthorized modifications to database records

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns in requests to /worksheet/del_work.jsp
• Deploy SentinelOne Singularity XDR to monitor for suspicious process behavior and network activity associated with exploitation attempts
• Configure intrusion detection systems (IDS) to alert on SQL injection signatures targeting the vulnerable endpoint
• Enable verbose logging on the database server to capture and analyze query patterns for anomalies

Monitoring Recommendations

• Monitor web server access logs for requests containing encoded or obfuscated SQL injection payloads targeting the ID parameter
• Set up alerts for database queries that deviate from normal application behavior patterns
• Track authentication and authorization events for signs of privilege escalation following successful exploitation
• Implement real-time monitoring of database connections and query execution times to detect time-based blind injection attempts

How to Mitigate CVE-2026-1120

Immediate Actions Required

• Restrict network access to the /worksheet/del_work.jsp endpoint using firewall rules or access control lists
• Deploy a Web Application Firewall (WAF) with SQL injection protection rules in front of the affected application
• Consider temporarily disabling the vulnerable functionality if it is not business-critical
• Monitor for exploitation attempts while awaiting a vendor patch or implementing permanent mitigations

Patch Information

No official patch is currently available from the vendor. The vendor was contacted early about this disclosure but did not respond. Organizations should monitor vendor communications and the VulDB entry for updates on patch availability. In the absence of an official fix, implementing the workarounds and compensating controls described below is strongly recommended.

Workarounds

• Implement input validation at the application layer to reject requests with SQL metacharacters in the ID parameter
• Use a reverse proxy or WAF to filter malicious requests before they reach the vulnerable application
• Restrict database user permissions to limit the impact of successful SQL injection attacks
• Isolate the affected system on a network segment with limited access to sensitive resources
• Consider deploying virtual patching through security tools until an official patch becomes available

Additional technical details and community discussion can be found in the GitHub CVE Issue Discussion and VulDB CTI ID #341712.