Packet Processing

How out-of-bounds read via unchecked memcpy happens in C packet processing and how to fix it

A critical out-of-bounds read vulnerability was discovered in `hep-tester/heptester.c` where `memcpy` calls at lines 200-201 read from fixed offsets in a packet buffer without verifying the buffer was large enough. An attacker could send a crafted packet shorter than 18 bytes to trigger the read, potentially leaking memory contents or crashing the capture agent. The fix adds a single bounds check against `pkthdr->caplen` before any memory copy operations.