In words.protocols.jabber.xmlstream in Twisted through 19.2.1 XMPP support did not verify certificates when used with TLS allowing an attacker to MITM connections.

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The vulnerability of the words.protocols.jabber.xmlstream function in the Twisted networking framework allows a attacker to execute a “man-in-the-middle” attack.

The vulnerability of the words.protocols.jabber.xmlstream function in the Twisted networking framework is related to authentication errors. Exploiting this vulnerability could allow a remote attacker to execute a “man-in-the-middle” attack...

DEBIAN-CVE-2019-12855

In words.protocols.jabber.xmlstream in Twisted through 19.2.1, XMPP support did not verify certificates when used with TLS, allowing an attacker to MITM connections...