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One post tagged with "Smashing The Stack"

Smashing the stack is a type of buffer overflow attack that involves manipulating the return address on the stack to redirect control flow to a malicious payload. This is done by overflowing a buffer with carefully crafted input, overwriting the return address with a pointer to the attacker's shellcode, and then returning to it when the program attempts to exit the function. By smashing the stack in this way, an attacker can execute arbitrary code on the compromised system.

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HTB | You know 0xDiablos | Write-Up

· 22 min read

Summary:​

We prepare for a challenge by preparing challenge files and testing the executable. Next, we perform static analysis using Ghidra to identify potential vulnerabilities. Upon discovering a buffer overflow vulnerability, we verify its existence and proceed to analyze the target architecture and endianness using pwntools' checksec feature.

With this information in hand, we use GDB and PEDA to identify the offset and address of the flag() function. We then craft a malicious payload using pwntools to smash the stack and exploit the vulnerability. Before submitting the exploit to the target machine, we verify its effectiveness against a local copy of the executable. After successfully exploiting the target, we submit our exploit and grab the recovered flag, declaring Challenge Completed once the task is accomplished.

Challenge Name: You know 0xDiablos | Difficulty: Easy | Category: Pwn