CVE-2022-23468 is a medium-severity buffer overflow vulnerability identified in the open-source project xrdp, specifically in versions prior to 0.9.21. xrdp is widely used to provide graphical login capabilities to remote machines via the Microsoft Remote Desktop Protocol (RDP). The vulnerability exists in the function xrdp_login_wnd_create(), where a buffer copy operation is performed without properly checking the size of the input data. This classic buffer overflow (CWE-120) flaw can lead to memory corruption, potentially allowing an attacker to execute arbitrary code or cause a denial of service (DoS) by crashing the service. The vulnerability arises because the input data length is not validated before being copied into a fixed-size buffer, making it possible for specially crafted input to overflow the buffer boundaries. There are no known workarounds for this issue, and mitigation relies on upgrading to xrdp version 0.9.21 or later, where the vulnerability has been addressed. Although no exploits have been observed in the wild to date, the nature of the vulnerability and its presence in a remote access service make it a significant risk if left unpatched. The vulnerability affects all deployments of xrdp prior to 0.9.21, which is commonly used on Linux-based systems to provide RDP access, including in enterprise and cloud environments.

For European organizations, the impact of this vulnerability can be substantial. xrdp is often deployed in environments where remote desktop access is critical, such as in IT administration, managed service providers, and cloud infrastructure. Exploitation could allow attackers to execute arbitrary code with the privileges of the xrdp service, potentially leading to full system compromise. This could result in unauthorized access to sensitive data, disruption of business operations through service crashes or ransomware deployment, and lateral movement within networks. Given the widespread use of Linux servers in European enterprises and public sector organizations, especially those adopting remote work models, the vulnerability poses a risk to confidentiality, integrity, and availability of critical systems. The absence of known exploits reduces immediate risk but does not eliminate the threat, as attackers may develop exploits targeting this vulnerability. Additionally, the vulnerability could be leveraged in targeted attacks against high-value infrastructure, including government agencies, financial institutions, and critical infrastructure providers in Europe.

To mitigate this vulnerability, European organizations should prioritize upgrading all xrdp deployments to version 0.9.21 or later, where the buffer overflow has been fixed. Given the lack of workarounds, patching is the primary defense. Organizations should inventory their environments to identify all systems running vulnerable xrdp versions, including less obvious deployments such as containerized environments or virtual machines. Network-level controls should be implemented to restrict RDP access to trusted IP addresses and VPNs to reduce exposure. Monitoring and logging of RDP sessions should be enhanced to detect anomalous activity indicative of exploitation attempts. Additionally, organizations should conduct regular vulnerability scanning and penetration testing focused on remote access services. For environments where immediate patching is not feasible, temporarily disabling xrdp or replacing it with alternative secure remote access solutions can reduce risk. Finally, organizations should ensure that endpoint detection and response (EDR) tools are configured to detect exploitation attempts related to buffer overflows and unusual process behaviors associated with xrdp.