Directory traversal, also known as path traversal, is an HTTP attack which allows attackers to access restricted directories and execute commands outside of the web server's root directory. This attack is also known as “dot-dot-slash”, “directory traversal”, “directory climbing” and “backtracking”. It is used by attackers to gain access to files and directories that are stored outside the web root folder. By manipulating variables that reference files with “dot-dot-slash (../)” sequences and its variations, or by using absolute file paths, attackers can access arbitrary files and directories stored on file system including application source code or configuration and critical system files. Directory traversal attacks can also be used to access restricted directories and execute commands outside of the web server's root directory.