webProhard

Where's Your HEAD At?

kalmarctf

Task: a Flask service cloned an attacker-controlled Git repository, created `headlocation`, then executed `git show HEAD` from inside that path. Solution: hide a bare repository at `headlocation`, force a promisor fetch for a missing object, and use repo-local `sshCommand` to run `/flagout` and exfiltrate the flag.

git command_execution suid git_clone bare_repository partial_clone promisor_remote sshcommand

buried_bare_repo_confusionpromisor_fetch_triggersshcommand_rceout_of_band_exfiltration

$ ls tags/ techniques/

git command_execution suid git_clone bare_repository partial_clone promisor_remote sshcommand

buried_bare_repo_confusionpromisor_fetch_triggersshcommand_rceout_of_band_exfiltration

Analysis

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$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

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