Logging into Tomcat Manager (port 8080) allows deployment of a WAR backdoor. Reverse shell obtained as user tomcat .

Can you view another user's profile by simply changing a numeric ID in the URL?

Suppose enumeration reveals a custom backup script or a tool running via a root cron job that suffers from a wildcard injection or an insecure path hijacking vulnerability. Alternatively, there may be a service binary that you can exploit using standard techniques found on GTFOBins.

The scan targets standard HTTP/HTTPS web endpoints alongside an SSH daemon reserved for credentialed remote access. Virtual Host Enumeration

After gaining a low-privilege shell (often as www-data or a service account named fail_user ), the box presents its ultimate challenge. The privilege escalation vector is not sudo -l , SUID binaries , or cron jobs.

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For example, attempting SQL injection might return:

Manual request interception using interception proxies reveals that the web platform handles user input poorly. Misconfigured parameters or fail-safe logic in the login routing create an exploit window. Attackers leverage these input validation oversights to bypass authentication mechanisms or induce arbitrary remote code execution (RCE) via web-exposed scripting features. Phase 3: Initial Foothold (User Flag)

Port 80 hosts a static HTML page with a single cryptic message:

If you are working on a machine where you've mapped this domain to an IP in your /etc/hosts file, you can follow this standard penetration testing methodology to solve it: 1. Enumeration (Reconnaissance)

You find nothing. You are stuck. You check your Burp Suite history. Every request is going through, but the responses are plain HTML. Then you notice something odd in the Host header. Burp is forwarding the IP address, but the server expects a domain name.

: Open, but usually a dead end for initial footbeds.

Once inside the initial environment, run basic enumeration scripts like LinPEAS or check internal configurations manually. whoami id Use code with caution.

Disable Git hooks for non-admin users in Gitea's app.ini .

Because Hack The Box targets frequently rely on virtual hosting, the local attacking machine must map the target's IP address to the intended domain. Analysts append the target IP address next to hackfail.htb inside the /etc/hosts file to ensure the web browser correctly handles the host headers. # Example /etc/hosts entry 10.10.11.X hackfail.htb Use code with caution. Phase 2: Web Application Analysis & Footprint

The security failures demonstrated across the hackfail.htb footprint offer valuable lessons for designing and securing systems: Attack Vector Security Breakdown Defensive Fix / Remediation Poor validation filters on incoming web requests.

Send the exploit payload via a POST or GET request using curl or Burp Suite to trigger a reverse shell:

Since dev_user had write permissions in the directory where utility.py lived, I could perform Python Library Hijacking . I swapped the real utility.py for a malicious one: import os os.system("/bin/bash") Use code with caution. Copied to clipboard