An issue was discovered in Gajim through 1.4.7. The vulnerability allows attackers, via crafted XML stanzas, to correct messages that were not sent by them. The attacker needs to be part of the group chat or single chat. The fixed version is 1.5.0.
Gajim 1.2.x and 1.3.x before 1.3.3 allows remote attackers to cause a denial of service (crash) via a crafted XMPP Last Message Correction (XEP-0308) message in multi-user chat, where the message ID equals the correction ID.