The vulnerability occurs because the broker does not properly close sessions or deallocate internal resources when clients send invalid CONNECT packets, either due to repeated connection attempts or failed authentication. As a result, the server may silently drop the connection or send a CONNACK response but leave resources allocated. This resource leak can be exploited by an attacker to create many half-open connections, exhausting system memory and file descriptors, which may lead to denial of service conditions on affected systems.

An attacker can cause a denial of service by exhausting memory and file descriptors on the server through numerous half-open connections. This may trigger the Linux Out-Of-Memory (OOM) killer, disrupting normal broker operations and potentially affecting availability.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, monitor for unusual numbers of half-open connections and consider limiting connection attempts or implementing rate limiting on CONNECT packets to mitigate resource exhaustion.