CVE-2019-0223

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.

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.

## Withdrawn Advisory This advisory has been withdrawn because the vulnerability only affects the **Qpid Proton C library** and not `org.apache.qpid:proton-j`. This link has been maintained to preserve external references. ## Original Description 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.

Mientras investigábamos el error PROTON-2014, descubrimos que en algunas circunstancias las versiones de Apache Qpid Proton 0.9 a 0.27.0 (librería de C y sus adaptaciones de lenguaje) pueden conectarse a un peer de forma anónima utilizando TLS *incluso cuando está configurado para verificar el certificado del peer* mientras se utiliza con versiones de OpenSSL anteriores a la 1.1.0. Esto significa que un ataque man in the middle podría ser construido si un atacante puede interceptar el tráfico TLS.