Bratarina -- Proving Grounds (write-up)¶

Difficulty: Easy Box: Bratarina (Proving Grounds) Author: dsec Date: 2025-09-11

TL;DR¶

SMTP service exploit gave initial shell. Straightforward foothold with a known vulnerability.¶

Target info¶

Host: 192.168.165.71
Services discovered via nmap

Enumeration¶

Nmap results

Service details

Directory brute force:

feroxbuster -u http://192.168.165.71 -w /usr/share/wordlists/dirb/common.txt -n

Feroxbuster results

Foothold¶

Exploit research

Exploit execution

Exploit success

Stabilized the shell. Note: the first PTY stabilization command did not work (had a space between ; and import pty), but the second command from revshells worked:

Shell stabilization

Proof

Lessons & takeaways¶

Watch for syntax errors in shell stabilization commands -- spacing matters
Always check SMTP services for known exploits