CVE-2024-22211 is a vulnerability identified in FreeRDP, an open-source implementation of the Remote Desktop Protocol (RDP) used widely for remote desktop clients. The flaw is an integer overflow occurring in the function freerdp_bitmap_planar_context_reset. Specifically, when processing the RDPGFX_RESET_GRAPHICS_PDU message, a malicious RDP server can craft this message to cause an integer overflow that leads to a heap-buffer overflow in the client. This overflow results from allocating buffers that are too small due to the integer wraparound, which can subsequently cause out-of-bounds read or write operations. However, the vulnerability does not allow direct data extraction over the network since the corrupted buffers are used solely for rendering images on the client side. The issue affects FreeRDP client versions prior to 2.11.5 and versions from 3.0.0 up to but not including 3.2.0. Server implementations and proxies based on FreeRDP are not impacted. The vulnerability requires a low privilege attacker controlling a malicious RDP server to interact with a client user who must initiate the connection (user interaction required). The CVSS v3.1 base score is 3.7 (low severity), reflecting the limited impact on confidentiality and the complexity of exploitation. No known exploits are currently in the wild, and no workarounds exist other than upgrading to patched versions 2.11.5 or 3.2.0 and above.

For European organizations, the primary risk lies in the use of FreeRDP clients to connect to potentially untrusted or compromised RDP servers. If an attacker controls or compromises an RDP server, they could exploit this vulnerability to cause heap-buffer overflows on client machines, potentially leading to application crashes or limited code execution scenarios that may affect client stability and availability. Although direct data theft over the network is not feasible, exploitation could be used as a vector for denial of service or to facilitate further client-side attacks. Organizations relying on FreeRDP clients for remote access, especially in sectors with high remote workforce adoption such as finance, healthcare, and government, could face disruptions or targeted attacks. The vulnerability’s requirement for user interaction and low privilege on the attacker side reduces the risk of widespread automated exploitation but does not eliminate targeted attacks. Given the widespread use of RDP in Europe and the increasing reliance on remote work, this vulnerability could impact operational continuity and client endpoint security if not addressed promptly.

European organizations should prioritize upgrading all FreeRDP client deployments to version 2.11.5 or 3.2.0 and later, where the vulnerability is patched. Network administrators should restrict RDP client connections to trusted servers only, employing network-level authentication (NLA) and VPNs to reduce exposure to malicious servers. Implementing strict firewall rules and monitoring RDP traffic for unusual patterns can help detect attempts to exploit this vulnerability. Endpoint protection solutions should be configured to detect abnormal application crashes or memory corruption events related to FreeRDP clients. Additionally, organizations should educate users about the risks of connecting to untrusted RDP servers and enforce policies that limit remote desktop connections to approved infrastructure. Since no workarounds exist, patching remains the most effective mitigation. Regular vulnerability scanning and asset inventory to identify affected FreeRDP versions will support timely remediation.