CVE-2023-28754
📋 TL;DR
This vulnerability allows attackers with permission to modify ShardingSphere-Agent YAML configuration files to execute arbitrary code by exploiting unsafe deserialization. Attackers can craft malicious YAML files that trigger remote code execution when the agent loads configuration. This affects all Apache ShardingSphere-Agent installations through version 5.3.2.
💻 Affected Systems
- Apache ShardingSphere-Agent
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over the affected server, enabling data theft, lateral movement, and persistent backdoor installation.
Likely Case
Privilege escalation leading to unauthorized access to databases and sensitive data, potentially enabling further attacks within the network.
If Mitigated
Limited impact due to restricted file modification permissions and network segmentation preventing external JAR loading.
🎯 Exploit Status
Exploitation requires file write permissions and knowledge of the target's configuration. Public exploit details exist in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apache ShardingSphere 5.4.0
Vendor Advisory: https://lists.apache.org/thread/p8onhqox5kkwow9lc6gs03z28wtyp1cg
Restart Required: Yes
Instructions:
1. Download Apache ShardingSphere 5.4.0 or later from official sources. 2. Replace existing ShardingSphere-Agent with patched version. 3. Restart all ShardingSphere services using the agent.
🔧 Temporary Workarounds
Restrict YAML file permissions
linuxSet strict file permissions on ShardingSphere-Agent configuration files to prevent unauthorized modifications.
chmod 600 /path/to/shardingsphere-agent.yaml
chown root:root /path/to/shardingsphere-agent.yaml
Network segmentation
linuxBlock outbound network access from ShardingSphere servers to prevent loading malicious JARs from external URLs.
iptables -A OUTPUT -p tcp --dport 80 -j DROP
iptables -A OUTPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Implement strict access controls on ShardingSphere configuration directories and files
- Monitor for unauthorized modifications to YAML configuration files using file integrity monitoring
🔍 How to Verify
Check if Vulnerable:
Check ShardingSphere-Agent version: grep 'version' /path/to/shardingsphere-agent.jar/META-INF/MANIFEST.MF or check application logs for version information.Check Version:
java -jar /path/to/shardingsphere-agent.jar --version 2>&1 | grep -i versionVerify Fix Applied:
Verify version is 5.4.0 or higher using the same method and ensure configuration files are not being deserialized with vulnerable SnakeYAML versions.📡 Detection & Monitoring
Log Indicators:
- Unusual YAML parsing errors in ShardingSphere logs
- Unexpected network connections to external URLs during agent startup
- Suspicious ClassLoader or ScriptEngineManager activity in JVM logs
Network Indicators:
- Outbound HTTP/HTTPS connections from ShardingSphere servers to unknown domains during startup
- Unexpected JAR downloads from external sources
SIEM Query:
source="shardingsphere.logs" AND ("YAML" OR "deserialization" OR "ClassLoader") AND ("error" OR "exception")