ICMP

ArubaOS 8.13.2.0 does not validate ICMP Echo Request source IPs against MAC/IP bindings or apply uRPF — attacker MAC with victim IP is accepted and replied to (CWE-290). Broadcast source IP (192.168.56.255) causes the controller to reply to ff:ff:ff:ff:ff:ff, delivering the reply to every host on the L2 segment (CWE-406). Two-machine evidence: Parrot OS attacker sends spoofed request, Windows victim receives unsolicited Echo Reply id=0xc101 confirmed in independent pcap. No ICMP request was sent from the victim. RFC 1122 §3.2.2.6 violation. Bugcrowd closed as expected behavior. No fix issued.

ICMP packets with incorrect checksums are silently dropped by the kernel before reaching the destination. RFC 1071 mandates 16-bit one’s complement sum: accumulate packet words in eax, handle odd trailing byte separately, fold the carry bits (shr r11d,16 → and eax,0xFFFF → add ax,r11w → adc ax,0), invert with not ax. The receiver repeats the same sum — result must be 0xFFFF for a valid packet. Full x64 Assembly implementation with register layout, loop termination, and ICMP header integration.

Linux and Windows ICMP Echo Requests differ in payload size (64B vs 40B), default content (timestamp vs alphabetical), and TTL values — forming OS-specific network fingerprints that NIDS use for traffic classification. Traffic mimicry replicates these signatures at the assembly level: 8-byte RDTSC timestamp emulation, sequential byte padding (0x10–0x1F), and strict 64-byte structural alignment bypass DPI anomaly detection without triggering empty-payload or entropy signatures.

Raw socket ICMP sniffing in x64 Assembly without libc: SOCK_RAW+IPPROTO_ICMP instructs the kernel to deliver only ICMP frames, filtering TCP/UDP at the socket layer. sys_recvfrom delivers the full frame including IP header — lea rsi,[sniffed_data+28] skips the 20-byte IPv4 header and 8-byte ICMP header to reach payload. IP address conversion: fetch each octet from sockaddr_in, repeatedly divide by 10 via div instruction, add 0x30 for ASCII, write digits backward into 16-byte buffer, insert 0x2E dot separators via conditional jump. Full source on GitHub.