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Bandit 30 Writeup

CTFOTW
Authors
  • Name
    Pablo
    Twitter
    @pablousu
  • Name
    Maylen Echavez
    Twitter
Table of Contents
levels

Concepts to consider

Git tag

A git tag is a reference to a specific point in a Git repository's history. It is used to mark important points, such as releases or significant changes. Tags are often used in a similar way to branches, but unlike branches, they are immutable; once created, they do not change. There are two types of tags in Git: lightweight and annotated.

bandit 30

Task

There is a git repository at ssh://bandit29-git@localhost/home/bandit29-git/repo via the port 2220. The password for the user bandit29-git is the same as for the user bandit29.

Clone the repository and find the password for the next level.

Solution

When cloning the repository, we can see that the log shows a single commit:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git log
commit d39631d73f786269b895ae9a7b14760cbf40a99f (HEAD -> master, origin/master, origin/HEAD)
Author: Ben Dover <noone@overthewire.org>
Date:   Thu Oct 5 06:19:45 2023 +0000

    initial commit of README.md

This shows the initial commit of the repository, authored by Ben Dover, with the message "initial commit of README.md".

Additionally, we use autocompletion to check if there are any other branches and find that there is a branch called secret. We then list the branches:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git branch
HEAD            master          origin/HEAD     origin/master   secret

This command lists all branches, showing that there is indeed a secret branch. We verify the current branch and see that we are on master:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git branch
* master

We then try to switch to the secret branch:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git branch secret
bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git branch
* master
  secret
bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git checkout secret
warning: refname 'secret' is ambiguous.
Switched to branch 'secret'

Here, we encounter a warning that 'secret' is ambiguous, but the branch switch is successful. We are now on the secret branch. Running git log again shows the same commit as in the master branch:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git log
commit d39631d73f786269b895ae9a7b14760cbf40a99f (HEAD -> secret, origin/master, origin/HEAD, master)
Author: Ben Dover <noone@overthewire.org>
Date:   Thu Oct 5 06:19:45 2023 +0000

    initial commit of README.md

This confirms that there are no new commits in the secret branch compared to the master branch.

Next, we list the tags to check for any additional information:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git tag
secret

We find a tag also named secret. We use git show to see the details of this tag:

bandit30@bandit:/tmp/tmp.G6nZtBcNFO/repo$ git show secret
warning: refname 'secret' is ambiguous.
OoffzGDlzhAlerFJ2cAiz1D41JW1Mhmt

The git show command reveals that the secret tag contains a string: OoffzGDlzhAlerFJ2cAiz1D41JW1Mhmt. This is the information we were looking for. Bingo!