This vulnerability in gnome-remote-desktop allows an unauthenticated remote attacker to open RDP connections without completing the handshake, thereby retaining connection-throttling slots indefinitely due to the lack of a pre-authentication handshake deadline. By exhausting the global connection limit, the attacker can prevent new RDP clients from connecting until the held sockets are closed. Exploitation requires connections from at least two distinct source IP addresses to fully utilize per-source and global connection limits. Authenticated RDP sessions remain unaffected. The vulnerability is classified as CWE-400 (Uncontrolled Resource Consumption) and has a CVSS v3.1 base score of 7.5 (high severity) with network attack vector, low complexity, no privileges or user interaction required, and an availability impact.

An attacker can cause a denial-of-service condition by exhausting the global connection limit for RDP connections in gnome-remote-desktop, preventing new clients from connecting. This affects availability but does not impact confidentiality or integrity. Existing authenticated sessions continue to function normally.

Red Hat advises disabling the RDP listener when it is not required or restricting access to the RDP port to trusted networks or hosts at the network boundary. There is currently no known application-level mitigation that allows unrestricted RDP access while preventing this issue. Users should follow the vendor advisory for updates on fixes or additional mitigations.