An easily exploitable flaw exists that could enable an anonymous hacker to cause a denial of service on many common FTP server platforms, including some public FTP servers run by software giants Adobe and HP. The vulnerability is in the glob() function, which is used to enable wildcard searches by file names. When exploited the hole can cause servers to become slow, unresponsive and even crash. Unlike previous FTP attacks like Gumblar, which remotely steals credentials, the GLOB flaw does not allow remote code to be executed on the affected system and does not appear to be widespread.
Source: https://threatpost.com/ftp-flaw-could-disable-wide-range-servers-100710/74561/