The Wocky module in Telepathy Gabble before 0.16.6 and 0.17.x before 0.17.4, when connecting to a "legacy Jabber server," does not properly enforce the WockyConnector:tls-required flag, which allows remote attackers to bypass TLS verification and perform a man-in-the-middle attacks.

A certain hashing algorithm in Telepathy Gabble 0.16.x before 0.16.5 and 0.17.x before 0.17.3 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a crafted message.