CVE-2023-43796

Synapse es un servidor doméstico Matrix de código abierto. Antes de las versiones 1.95.1 y 1.96.0rc1, la información del dispositivo almacenado en caché de usuarios remotos se puede consultar desde Synapse. Esto se puede utilizar para enumerar los usuarios remotos conocidos por un servidor doméstico. Se recomienda a los administradores del sistema que actualicen a Synapse 1.95.1 o 1.96.0rc1 para recibir un parche. Como workaround, se puede utilizar `federation_domain_whitelist` para limitar el tráfico de federación con un servidor doméstico.

It was discovered that Synapse network policies could be bypassed via specially crafted URLs. An attacker could possibly use this issue to bypass authentication mechanisms. It was discovered that Synapse exposed cached device information. An attacker could possibly use this issue to gain access to sensitive information. It was discovered that Synapse could be tricked into rejecting state changes in rooms. An attacker could possibly use this issue to cause Synapse to stop functioning properly, resulting in a denial of service. This issue was only fixed in Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.