The C client and C-based client bindings in the Apache Qpid Proton library before 0.13.1 on Windows do not properly verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate when using the SChannel-based security layer, which allows man-in-the-middle attackers to spoof servers via an arbitrary valid certificate.

The Python client in Apache Qpid before 2.2 does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

The AMQP type decoder in Apache Qpid 0.20 and earlier allows remote attackers to cause a denial of service (memory consumption and server crash) via a large number of zero width elements in the client-properties map in a connection.start-ok message.

The default configuration for Apache Qpid 0.20 and earlier, when the federation_tag attribute is enabled, accepts AMQP connections without checking the source user ID, which allows remote attackers to bypass authentication and have other unspecified impact via an AMQP request.

Integer overflow in the qpid::framing::Buffer::checkAvailable function in Apache Qpid 0.20 and earlier allows remote attackers to cause a denial of service (crash) via a crafted message, which triggers an out-of-bounds read.

The serializing/deserializing functions in the qpid::framing::Buffer class in Apache Qpid 0.20 and earlier allow remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors. NOTE: this issue could also trigger an out-of-bounds read, but it might not trigger a crash.

Apache Qpid 0.17 and earlier does not properly restrict incoming client connections, which allows remote attackers to cause a denial of service (file descriptor consumption) via a large number of incomplete connections.