Yonyou U8 CRM Arbitrary File Read via getemaildata.php

Yonyou U8 CRM before V16.5 and V18 contains an arbitrary file read vulnerability in /ajax/getemaildata.php that allows unauthenticated attackers to bypass authentication using the DontCheckLogin=1 parameter and read arbitrary files via an unvalidated filePath parameter. Attackers can exploit this flaw to read sensitive files outside the web application directory, including configuration files containing database or service credentials. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-14.