A critical heap-based buffer overflow in FreeRDP allows a malicious RDP server to execute arbitrary code on the client machine via clipboard operations.

The vulnerability exists in the CliprdrStream_Read function, which fails to properly validate the size of data copied into a heap buffer. This allows an unauthenticated remote attacker who controls the RDP server to trigger an out-of-bounds write.

Exploitation of this vulnerability can lead to remote code execution on the client system, granting the attacker control over the user's workstation. With a CVSS score of 9.6, this is an extremely severe vulnerability that could lead to full system compromise and lateral movement within the network.

Immediate Action: Upgrade FreeRDP to version 3.30.0 or later immediately.

Proactive Monitoring: Monitor for suspicious RDP session activity or unexplained crashes of the FreeRDP client process, which may indicate an exploitation attempt.

Compensating Controls: Restrict RDP clipboard sharing features via Group Policy or configuration files where possible until the software can be updated.

Public Exploit Available: Unknown

Given the potential for remote code execution, this update should be treated with the highest urgency. All affected FreeRDP clients must be patched to version 3.30.0 to mitigate the risk of host compromise.