Intermesh Group-Office 3.3.0 before 3.5.5 contains an unauthenticated path traversal vulnerability in compress.php that allows remote attackers to read arbitrary files by manipulating the 'file' parameter. Attackers can send GET requests to /compress.php with '../' sequences in the 'file' parameter, which is appended to the cache path and passed to readfile(), to read files such as /etc/passwd. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-21.