A critical out-of-bounds write vulnerability in FreeRDP may lead to arbitrary code execution or system instability when processing malicious RDP traffic.

This vulnerability involves incorrect calculation of buffer sizes (CWE-131) leading to an out-of-bounds write (CWE-787). An attacker can trigger this condition by sending specially crafted packets to an affected RDP client or server, which may result in memory corruption.

Successful exploitation of this flaw could allow an attacker to crash the affected service or potentially execute arbitrary code with the privileges of the application. Given the high CVSS score of 7.5, this poses a substantial risk to systems relying on FreeRDP for remote access, as it could facilitate unauthorized system access or complete service disruption.

Immediate Action: Upgrade to FreeRDP version 3.27.1 or later to incorporate the necessary memory safety fixes.

Proactive Monitoring: Review system and network access logs for anomalous RDP traffic patterns or unexpected service crashes.

Compensating Controls: Restrict access to RDP services by limiting source IP addresses via firewall rules and using VPNs to prevent public exposure of the protocol.

Public Exploit Available: Unknown

Organizations utilizing FreeRDP must prioritize the upgrade to version 3.27.1 to remediate the buffer calculation errors. Due to the existence of a proof-of-concept, the window for potential exploitation is narrowing, and rapid deployment of the security update is essential to protect critical remote access infrastructure.