picoCTF Solutions
picoCTF 2026General SkillsMedium

Failure Failure

Published: March 20, 2026

Description

Welcome to Failure Failure -- a high-available system. This challenge simulates a real-world failover scenario where one server is prioritized over the other. A load balancer stands between you and the truth -- and it won't hand over the flag until you force its hand.

Setup

Launch the challenge instance and note the host and port.

The service sits behind a load balancer that routes between a primary and failover server.

Solution

  1. Step 1SSH into the challenge server
    Use the provided credentials to SSH into the challenge instance. The system runs a primary service and a secondary (fallback) service.
    ssh <user>@<HOST> -p <PORT_FROM_INSTANCE>
  2. Step 2Stop the primary service
    The primary service is running and takes priority. Stop it with systemctl so the secondary service (which contains the flag) becomes active.
    sudo systemctl stop primary.service
    # Check that the secondary is now active:
    sudo systemctl status
  3. Step 3Read the flag from the secondary service
    Watch the journal output -- once the primary service is down, the secondary activates and prints the flag to the system journal.
    journalctl -f
    # Or check the service output directly
    sudo systemctl status secondary.service

Flag

picoCTF{f41lur3_f41lur3_...}

The flag lives in the secondary (failover) service. SSH in and stop the primary service with systemctl -- the secondary takes over and reveals the flag via journalctl.