While investigating bug PROTON-2014, we discovered that under some circumstances Apache Qpid Proton versions 0.9 to 0.27.0 (C library and its language bindings) can connect to a peer anonymously using TLS *even when configured to verify the peer certificate* while used with OpenSSL versions before 1.1.0. This means that an undetected man in the middle attack could be constructed if an attacker can arrange to intercept TLS traffic.
The qpidd broker in Apache Qpid 0.30 and earlier allows remote authenticated users to cause a denial of service (daemon crash) via an AMQP message with (1) an invalid range in a sequence set, (2) content-bearing methods other than message-transfer, or (3) a session-gap control before a corresponding session-attach.
qpidd in Apache Qpid 0.30 and earlier allows remote attackers to cause a denial of service (daemon crash) via a crafted protocol sequence set. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-0203.
Unspecified vulnerability in Apache Qpid 0.30 and earlier allows remote attackers to bypass access restrictions on qpidd via unknown vectors, related to 0-10 connection handling.