A critical use after free vulnerability in FreeRDP prior to version 3.22.0 could allow an unauthenticated attacker to cause a denial of service condition.

The vulnerability exists within the video_timer component, where client notifications occur after the control channel is closed. This action results in the dereferencing of a freed callback, which is a classic use after free memory corruption flaw that can be triggered by an unauthenticated attacker.

The exploitation of this vulnerability leads to a denial of service, which can disrupt critical remote access operations relying on the FreeRDP implementation. Given the CVSS score of 7.5, this high severity rating reflects the ease of exploitability and the potential for service instability in production environments. Organizations utilizing this protocol for remote connectivity may face significant operational downtime if this flaw is successfully leveraged.

Immediate Action: Update the FreeRDP software to version 3.22.0 or later to incorporate the vendor provided fix.

Proactive Monitoring: Monitor system logs for unexpected service crashes or restarts of the FreeRDP process, which may indicate attempted exploitation.

Compensating Controls: Ensure that network boundaries are restricted to authorized users via VPN or mTLS to reduce the attack surface, as this flaw is remotely exploitable.

Public Exploit Available: No

The vulnerability presents a clear risk to the stability of systems utilizing FreeRDP. Security teams should prioritize the deployment of version 3.22.0 across all affected endpoints to eliminate the potential for denial of service attacks. Immediate patching is the most effective method to mitigate this risk.