Puskuriläpäisy

Puskuriläpäisy, often translated as buffer overflow or buffer overrun, is a software vulnerability that occurs when a program attempts to write data beyond the allocated memory buffer. This can happen when a program receives more data than it is designed to handle, leading to the excess data overwriting adjacent memory locations. The consequences of a buffer overflow can range from minor program glitches to severe security risks.

When data overwrites adjacent memory, it can corrupt or replace legitimate program instructions or data. In the worst-case scenario, an attacker can craft specific input that overwrites a return address on the program's call stack. By controlling this return address, the attacker can redirect the program's execution flow to malicious code, often referred to as shellcode. This allows the attacker to execute arbitrary commands on the affected system, potentially leading to unauthorized access, data theft, or system compromise.

Preventing puskuriläpäisy involves careful programming practices and the use of secure coding techniques. Developers can implement bounds checking to ensure that data written to a buffer does not exceed its allocated size. Modern programming languages and compilers often provide built-in protections, such as safe string handling functions and stack canaries, which can detect and mitigate buffer overflow attempts. Operating systems also employ memory protection mechanisms like Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to make exploitation more difficult. Nonetheless, buffer overflows remain a persistent security concern in software development.