Let’s break down exactly how to solve it. When you navigate to the provided endpoint (let’s call it http://target/challenge2/ ), you are greeted with a raw Apache-style directory listing:
Index of /challenge2 [PARENTDIR] Parent Directory [DIR] assets/ [TXT] readme.txt [?] flag.txt
Developers often forget that .git directories contain the entire history of a project, including deleted secrets. The "index" in Git isn't just a list of files—it's a staging area for your next commit. If an attacker can read it, they can travel back in time.
The flag is rarely the file named "flag.txt." Step 2: Analyzing the "Index" The phrase "index of challenge 2" is the clue itself. It suggests we need to think about how indices work—both in databases and in file structures. index of challenge 2
Cracking the Code: A Deep Dive into the "Index of Challenge 2"
The subject line reads: — and at first glance, that might seem like a broken server message or a simple directory listing. But as any seasoned pentester will tell you, a naked directory index is rarely an accident. It’s an invitation.
rm .git/index git reset HEAD . Suddenly, files that were "deleted" or hidden reappear. You’ll see a file named backup_ flag.txt (without the space) or user_flag.enc . After restoring the Git index, run ls -la . You’ll find a symlink or a hidden file like .secret/creds . Let’s break down exactly how to solve it
Happy hacking. Have a different approach to "index of challenge 2"? Drop your methodology in the comments below.
openssl enc -d -aes-256-cbc -in user_flag.enc -out flag.txt -pass pass:CTFgit_is_not_backup And there it is:
Final Thoughts Challenge 2 teaches a critical real-world lesson: Directory indexing + exposed version control = Game over. If an attacker can read it, they can travel back in time
Decode the .enc file using the key found in the Git history ( git reflog ):
User: pentest_low Note: The .git index is corrupted. Restore HEAD. Bingo. This isn't a standard web challenge anymore. This is a challenge. Step 3: The Exploit - Restoring the Index If the .git folder is exposed (try /challenge2/.git/ ), and you see a directory listing there, you can download the entire repo using wget or git-dumper .
At first, you click flag.txt excitedly. But you’re met with a 403 Forbidden or a decoy message: "Not this time, hacker."