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Buffer overflow is a security weakness that hackers can exploit to gain unauthorized access to a computer system. This happens when a program stores more data in a buffer than it's supposed to, causing it to overwrite nearby memory locations. When hackers identify and take advantage of these vulnerabilities, it's called exploit development.

 

One common way hackers exploit buffer overflows is by using stack-based attacks. In this type of attack, the hacker overwrites a function's return address on the program stack, giving them control of the program's flow. This allows them to execute malicious code, such as launching a shell or other harmful actions. To prevent buffer overflow attacks, software developers use techniques like bounds checking and stack canaries. However, despite these protective measures, hackers continue to develop techniques like rop and rtl to exploit even well-protected systems.

 

For example, the 'scanf' function can be particularly risky because it doesn't limit the size of user inputs, making it vulnerable to malicious inputs. Modern Linux software often uses canaries and ASLR to protect against buffer overflow attacks. Canaries insert random addresses to detect buffer overflow, while ASLR randomizes memory addresses. Nonetheless, there are still ways for hackers to exploit these protections.