The HackFail machine highlights critical security flaws often found in enterprise environments:
: Check for exposed .git directories or backup files (e.g., .env , config.php ) that might contain credentials.
Now, when you visit http://hackfail.htb in your browser, the web server actually has a virtual host configuration for hackfail.htb (perhaps a default catch-all). The page changes. You start enumerating hackfail.htb —checking subdomains, looking for hidden directories. You are now completely off-target. hackfail.htb
If it's an active machine, I can only provide general guidance on methodology rather than specific flags.
Checking sudo -l might reveal that the current user can run a specific binary (e.g., find , vim , or a custom script) with root privileges, which can be exploited using GTFOBins. You start enumerating hackfail
Use ffuf or Gobuster to brute-force subdomains by injecting names into the HTTP host header. Filter out the baseline response size to eliminate false positives:
Common CVEs seen on hackfail.htb walkthroughs: Checking sudo -l might reveal that the current
The stack trace includes a path: /opt/hackfail/lib/FailAuth.class . Attempting to retrieve this .class file directly fails, but a path traversal via ?debug=../../../../opt/hackfail/lib/FailAuth leaks the compiled bytecode — downloadable after URL encoding.
HackFail HTB Walkthrough: Exploiting Misconfigured Fail2ban and Container Escapes
HackFail is a medium-difficulty Linux machine on Hack The Box that highlights the dangers of insecure automation, misconfigured log parsers, and container breakouts. This article provides a comprehensive, step-by-step guide to exploiting this machine, moving from initial footprinting to root access. Phase 1: Enumeration and Port Scanning