A flaw was found in gnome-remote-desktop as shipped in Red Hat Enterprise Linux. In the VNC TLS I/O handlers, retryable GnuTLS results (GNUTLS_E_AGAIN and GNUTLS_E_INTERRUPTED) are handled with an unbounded busy loop instead of yielding to the event loop. A remote attacker who can reach an enabled VNC TLS listener can cause the event-loop thread to spin at high CPU with no forward progress, resulting in denial of service.
If VNC is not required, disable the gnome-remote-desktop VNC service. If it must remain enabled, restrict the VNC listener to trusted hosts or management networks using host-based firewall rules.