CWE-121 (栈缓冲区溢出) — Vulnerability Class 3231

CWE-121 represents a critical memory safety weakness where program data exceeds the allocated bounds of a stack-allocated buffer, corrupting adjacent memory structures. Attackers typically exploit this vulnerability by injecting malicious payloads that overwrite the function’s return address or saved frame pointer, thereby hijacking control flow to execute arbitrary code with the privileges of the compromised process. This exploitation is particularly dangerous because stack buffers are local variables, making the attack surface common in low-level languages like C and C++. Developers mitigate this risk by enforcing strict input validation, utilizing safe string handling functions that prevent unbounded writes, and adopting modern programming languages with automatic memory management. Additionally, implementing compiler-level protections such as stack canaries and Address Space Layout Randomization significantly raises the barrier for successful exploitation, ensuring system integrity remains intact against buffer overflow attempts.