Exploit Dev — Stack Canaries

The stack canary is the last classic mitigation: a random cookie between your buffer and the saved return address, checked in the epilogue, so a plain overflow is detected and aborted. The bypass is simple once you have a leak — read the canary, then write the same value back so the check passes. We cover the anatomy and its null low byte, leaking via a format string, the payload layout, brute-forcing on forking servers, and partial overwrites.