Local privilege escalation using a backup with insecure access rights

by FelixBauer 9 months ago

GNU/Linux ◆ foot ◆ zsh 225 views

The user nobody find itself on a Linux system, looks around and finds a directory /backup with a tar archive that contains /etc, /home, and /root. So it also contains the .ssh directory of user felix and a ssh key that is not password protected. Extracting the key to /tmp user nobody logs in as user felix.

When creating the backup the umask value was the default 022 so the file permissions result -rw-r–r–.

Since the backup is created with root permissions nobody can extract and access EVERYTHING

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