An information leak exists in the handling of the MXIT protocol in Pidgin. Specially crafted MXIT data sent via the server could potentially result in an out-of-bounds read. A malicious user, server, or man-in-the-middle can send an invalid size for an avatar which will trigger an out-of-bounds read vulnerability. This could result in a denial of service or copy data from memory to the file, resulting in an information leak if the avatar is sent to another user.
https://security.gentoo.org/glsa/201701-38
http://www.ubuntu.com/usn/USN-3031-1
http://www.talosintelligence.com/reports/TALOS-2016-0135/
http://www.securityfocus.com/bid/91335