A buffer overflow vulnerability exists in the handling of the MXIT protocol Pidgin. Specially crafted data sent via the server could potentially result in a buffer overflow, potentially resulting in memory corruption. A malicious server or an unfiltered malicious user can send negative length values to trigger this vulnerability.
https://security.gentoo.org/glsa/201701-38
http://www.ubuntu.com/usn/USN-3031-1
http://www.talosintelligence.com/reports/TALOS-2016-0120/
http://www.securityfocus.com/bid/91335