Gadu-Gadu 7.20 does not properly handle MS-DOS device names in filenames, which allows remote attackers to (1) cause a denial of service (hang) via an image filename of AUX: sent twice (hang), or (2) write to the LPT1 port via a filename of "LPT1:".
https://exchange.xforce.ibmcloud.com/vulnerabilities/23148
http://www.securityfocus.com/bid/15520/
http://marc.info/?l=bugtraq&m=113261573023912&w=2
http://archives.neohapsis.com/archives/fulldisclosure/2005-11/0658.html