shared × unstructured — bad data written permanently, and it spreads

Buffer Overflow (Out-of-Bounds Write)

An unchecked length writes past the buffer into adjacent, shared memory.

01the recipe

In the wild

compound ofPointer MismanagementIndex Out of Bounds & Missing KeysCWE-120 Unchecked Buffer CopycompoundCWE-787 OOB Write

example.c

/* SMELL: unchecked length writes past the buffer into adjacent memory.
   (pointer-mismanagement x index-out-of-bounds) */
char name[16];
strcpy(name, input);     /* input over 15 chars -> overwrites the stack */

/* RIGHT: bound the write to the buffer you actually own. */
char name[16];
snprintf(name, sizeof name, "%s", input);   /* truncates, never overflows */

The missing bounds check (unstructured) plus a raw pointer write (shared memory) corrupts whatever sits past the buffer -- often the return address.

// observed

overflow: corrupts the return address; crash or code exec
bounded:  safely truncated, memory intact

02weakness catalog

Mapped weaknesses (CWE)

On its own, this defect is catalogued by MITRE as one or more of these weaknesses. The exploitable vulnerability usually appears only when it chains or combines with another.