MCabber before 1.0.4 is vulnerable to roster push attacks, which allows remote attackers to intercept communications, or add themselves as an entity on a 3rd party's roster as another user, which will also garner associated privileges, via crafted XMPP packets.
https://usn.ubuntu.com/4506-1/
https://lists.debian.org/debian-lts-announce/2020/06/msg00031.html
https://gultsch.de/gajim_roster_push_and_message_interception.html
https://bitbucket.org/McKael/mcabber-crew/commits/6e1ead98930d7dd0a520ad17c720ae4908429033/raw
http://www.securityfocus.com/bid/94862
http://www.openwall.com/lists/oss-security/2017/02/09/29
http://www.openwall.com/lists/oss-security/2016/12/11/2
http://lists.opensuse.org/opensuse-updates/2017-01/msg00130.html