Race Condition — Hackviser

The Race Condition lab on HackViser (often part of Certified Associate Penetration Tester or CAPT prep) focuses on exploiting the timing gap between a server's security checks and its final execution. Challenge Overview

threads = [] for _ in range(30): t = threading.Thread(target=send) t.start() threads.append(t) race condition hackviser

Here is the pseudo-code of the vulnerable binary: The Race Condition lab on HackViser (often part

Race conditions are a type of vulnerability that can have significant consequences if exploited by malicious actors. The hackviser community and other hackers have demonstrated the potential for exploiting these vulnerabilities to gain unauthorized access to systems and data. By understanding the types of race conditions, tools, and techniques used by hackers, developers and system administrators can take steps to prevent and mitigate these vulnerabilities. Regular updates, secure coding practices, and synchronization primitives can help prevent the exploitation of race conditions and protect sensitive data. Enter the Hackviser: Thinking Like the Machine A

def handleResponse(req, interesting): table.add(req)

Enter the Hackviser: Thinking Like the Machine

A traditional hacker looks for logic flaws. A Race Condition Hackviser, however, looks for timing flaws. The term "hackviser" implies a visual or diagnostic layer that helps the attacker see the slices of time where the system is vulnerable.

| Target | ( \Delta t ) | Success (no hackviser) | Success (with hackviser) | Time to exploit | |--------|---------------|------------------------|--------------------------|------------------| | TOCTOU (file) | 50 µs | 2% | 96% | 2 min | | Double redeem | 15 ms | 18% | 94% | 30 sec | | Futex wake | 220 ns | 1% | 89% | 8 min |

  1. Initial Request: The exploit would send a request to the chatbot, which would then be broken down into smaller tasks and executed by multiple threads.
  2. Thread Creation: As the threads were created, the exploit would inject a malicious payload into one of the threads, which would then be executed concurrently with the other threads.
  3. Synchronization Failure: Due to the lack of proper synchronization, the malicious thread would access the shared resource before the other threads had a chance to complete their tasks, effectively bypassing security checks.
  4. Payload Execution: The malicious payload, designed to evade detection, would then be executed, granting the hackers control of the chatbot's processes.