Race Condition Hackviser -

If you want to get good at binary exploitation, don't ignore the low-hanging fruit. Sometimes, the kernel’s scheduler is your best exploit primitive.

// vulnerable.c if (access("/tmp/debug.log", F_OK) != 0) O_WRONLY, 0600); write(fd, "User data", 10); close(fd); else printf("File already exists.\n");

Race Conditions Vulnerabilities I | by Ehxb - InfoSec Write-ups race condition hackviser

: Checks balance simultaneously. (Balance is still $100). Thread 1 : Approves the deduction and sends $100.

UPDATE users SET balance = balance - 50 WHERE id = 123 AND balance >= 50; Use code with caution. If you want to get good at binary

To exploit a on a platform like Hackviser to "generate a feature" (likely bypassing a restriction to access a premium feature or performing an action multiple times), you need to take advantage of the tiny time window between a security check and the final action.

: The application performs the action based on the check (e.g., "Deduct $100 and dispense the cash"). (Balance is still $100)

Double-spending credits or withdrawing more than a balance allows.

Casting multiple votes when only one is permitted per user. ## How to Hunt for Them

# Exploit code def exploit(chatbot, malicious_payload): # Create a new thread for the malicious payload malicious_thread = threading.Thread(target=chatbot.execute_task, args=(malicious_payload,)) malicious_thread.start()

coupon=WELCOME10'''