OpenHarness SSRF über web_fetch und web_search

The SSRF vulnerability in OpenHarness allows attackers to craft malicious requests that the OpenHarness agent will execute on behalf of the attacker. This can lead to unauthorized access to private HTTP services running on the same host or network as the OpenHarness agent. Attackers could exploit this to read response bodies from local development services, cloud metadata endpoints (potentially exposing credentials), admin panels, or other private HTTP services. The potential impact includes data exfiltration, privilege escalation, and potentially even remote code execution if the accessed services are vulnerable. This vulnerability shares similarities with other SSRF exploits where attackers leverage trusted internal connections to access restricted resources.

Organizations deploying OpenHarness in environments with sensitive internal services, particularly those utilizing cloud metadata endpoints or local development services, are at increased risk. Shared hosting environments where OpenHarness agents have broad network access are also particularly vulnerable.

• python / server:

import requests
import os

def check_ssrf(url):
    try:
        response = requests.get(url, timeout=5)
        print(f"[+] URL {url} accessible. Status code: {response.status_code}")
        return True
    except requests.exceptions.RequestException as e:
        print(f"[-] URL {url} not accessible: {e}")
        return False

# Example usage (replace with internal service URLs)
internal_urls = ["http://localhost:8080/admin", "http://169.254.169.254/latest/meta-data/", "http://127.0.0.1:5000/api/v1/users"] # Example URLs
for url in internal_urls:
    check_ssrf(url)

• linux / server:

journalctl -u openharness -f | grep -i "web_fetch" # Monitor for web_fetch calls

• generic web:

curl -I http://<openharness_host>/api/v1/tools/web_fetch # Check endpoint exposure

1. 2026-04-17Disclosure

   disclosure

1. Reserviert2026-04-13
2. Veröffentlicht2026-04-17
3. EPSS aktualisiert2026-04-25

The primary mitigation for CVE-2026-40516 is to upgrade OpenHarness to version bd4df81f634f8c7cddcc3fdf7f561a13dcbf03ae or later. If an immediate upgrade is not feasible, consider implementing temporary workarounds such as restricting network access from the OpenHarness agent to only necessary resources. Additionally, implement strict input validation on all parameters passed to the webfetch and websearch tools to prevent attackers from manipulating the target addresses. WAF rules can be configured to block requests to RFC1918, link-local, and other non-public addresses. After upgrading, confirm the fix by attempting to invoke the webfetch and websearch tools with crafted URLs targeting internal services and verifying that access is denied.