![]() Shell in Prompt #!/bin/bash read -p "What's you name: " Copied! ls -al /usr/local/Īssume we can write an arbitrary binary file under /usr/sbin, we can create a payload in there.įor example, we create a python binary under /usr/sbin. Instead we need to check if we have permission to write each path. If we can execute some command as root but env_reset and secure_path are set, we cannot override the PATH environment variable. Now run the command as root with setting the PATH. sudo -lĪs the previous section, prepare the payload. If you found there is a SETENV: in sudoers, you can set the PATH when running the command. Next, change the permission for allowing to execute it.Īnd add the path to the environment. If you can confirm that it can be executed as root without password, create the same named command in the arbitrary folder in which you can write files. If you are allowed to execute some command, you can forge the contents of the command. We might be able to get a root shell as follow. If we find the following result for sudoers, (ALL, !root) NOPASSWD: /bin/bash So it's recommended to look for in there.Īlso we might see from following files. If you don't trust them, don't give them root access.GTFOBins provides a wide variety of payloads to privilege escalation. If you give someone root access, they have root access and you have to trust them. There's no way to allow a user to run almost every command and only block a few. Or they could run sudo visudo and edit the sudoers rules. Or they could write eval "$(stdin)" into an executable file and run that with sudo. If you wanted to block users from running a shell as root, you'd need to block sudo sh as well. sudo -i is a shortcut for running the target user's default shell: it's equivalent to sudo bash or sudo sh or sudo zsh or similar. If your concern is that users can run a shell as root, and you'd want them to “only run specific commands”: a shell is a specific command. (Except logs stored on a remote machine then, at most, you can guarantee that the logs will contain the way the users gained root access.) Yes, so what? Being root allows them to turn off auditing and to delete logs. They are now as root, and those behaviour or actions run from user root are not logged without installing any third party auditd systems or tools allowing them to run arbitrary commands as root via sudo) is another. Yes, so what? Giving someone the root password is one method to allow them to access the root account. Now they are as root does not need to know the root password If you don't want to allow users to run commands as root, don't allow them access to the root account, via sudo or otherwise. Yes, they can, if they have been explicitly authorized to do so by adding the appropriate lines in the sudoers file. They can also just do sudo su or sudo -i to switch to root user without knowing root user password If you're the admin, you can be the admin… If you are the admin, you can have some users with sudo group level privileges ![]() Please correct me if my concerns or opinion are wrong. For me this seems like a cheat bypass code. I guess my questions is why linux allow this. Auditing and logging - They are now as root, and those behaviour or actions run from user root are not logged without installing any third party auditd systems or tools.Because now they are as root does not need to know the root password. In my opinion (correct me if i am wrong) - this is a big issue for security and also defeat the whole purpose of Linux structures.But they can also just do sudo su or sudo -i to switch to root user without knowing root user password. Now they will require to enter sudo command to do any root admin level commands or operations. And without giving them root password, they will not able to login or switch to root user (normal condition ofc). So if you are the admin, you can have some users with sudo group level privileges. I have a question recently discover that apparently you can 'bypass' the needs to know root user password and just switch straight in as root user. ![]()
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