CVE-2025-56769
📋 TL;DR
A vulnerability in chinabugotech hutool's QLExpressEngine class allows attackers to execute arbitrary expressions, leading to arbitrary method invocation and potential remote code execution. This affects all applications using vulnerable versions of the hutool library. Attackers could exploit this to gain unauthorized access or control over affected systems.
💻 Affected Systems
- chinabugotech hutool
📦 What is this software?
Hutool by Hutool
⚠️ Risk & Real-World Impact
Worst Case
Full remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Arbitrary method execution allowing attackers to manipulate application behavior, access sensitive data, or disrupt services.
If Mitigated
Limited impact through proper input validation and sandboxing, potentially preventing expression execution.
🎯 Exploit Status
Exploitation requires understanding of QLExpress syntax and the ability to inject expressions. No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.8.4
Vendor Advisory: https://github.com/chinabugotech/hutool/issues/3994
Restart Required: No
Instructions:
1. Update hutool dependency to version 5.8.4 or later in your project's build configuration (pom.xml for Maven, build.gradle for Gradle). 2. Rebuild and redeploy your application. 3. Verify the updated version is being used at runtime.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation to reject any untrusted expressions before they reach QLExpressEngine.
Sandbox Configuration
allConfigure QLExpressEngine with restricted sandbox settings to limit available methods and classes.
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems from critical assets
- Deploy web application firewall (WAF) rules to detect and block expression injection attempts
🔍 How to Verify
Check if Vulnerable:
Check your project's dependency management file (pom.xml or build.gradle) for hutool version. If version is below 5.8.4, you are vulnerable.Check Version:
For Maven: mvn dependency:tree | grep hutool. For Gradle: gradle dependencies | grep hutool.Verify Fix Applied:
After updating, verify the runtime version by checking the application's classpath or using: System.out.println(Class.forName("cn.hutool.extra.expression.engine.ql.QLExpressEngine").getProtectionDomain().getCodeSource().getLocation())📡 Detection & Monitoring
Log Indicators:
- Unusual QLExpress evaluation errors
- Suspicious expression patterns in input logs
- Unexpected method invocation logs
Network Indicators:
- HTTP requests containing QLExpress syntax patterns
- Unusual outbound connections from application servers
SIEM Query:
source="application_logs" AND ("QLExpress" OR "expression.engine") AND ("error" OR "exception")