Out-of-Bounds Writes

Sat, 21 Jun 2025 00:00:00 +0000

Out-of-bounds writes (CWE-787) are the single most dangerous class of memory corruption vulnerabilities on the SANS/CWE Top 25, and they’ve held that position for years. The reason is clear once you dig into the mechanics: writing past the end of a buffer can overwrite return addresses, function pointers, vtable entries, and adjacent heap metadata, giving attackers arbitrary code execution. Unlike higher-level languages where the runtime catches array index violations, C and C++ silently corrupt memory, and the consequences may not manifest until thousands of instructions later. Even Rust, with its ownership model, is vulnerable when unsafe blocks bypass the borrow checker. In this post I’ll dissect out-of-bounds writes in C, C++, and Rust, from the classic strcpy overflow to the subtle off-by-one in pointer arithmetic that can survive expert review.

Out-of-Bounds Write on guy@secdev.uk

Out-of-Bounds Writes