CVE-2023-5380 is a use-after-free vulnerability identified in the xorg-x11-server component of Red Hat Enterprise Linux 7. The flaw manifests in a very specific and legacy configuration known as Zaphod mode, which supports multi-screen setups with multiple protocol screens. The vulnerability occurs when the pointer is warped from within a window on one screen to the root window of another screen, and the original window is destroyed followed by the destruction of another window. This sequence leads to a use-after-free condition in the X server, causing it to crash and resulting in a denial of service. The vulnerability requires local access with low privileges (AV:L/PR:L) and has a high attack complexity (AC:H), meaning exploitation is difficult and requires specific conditions. There is no requirement for user interaction (UI:N), and the scope is unchanged (S:U). The impact is limited to availability (A:H) with no confidentiality or integrity impact. No known exploits are currently in the wild, and no patches were linked at the time of publication. This vulnerability primarily affects legacy systems still running Red Hat Enterprise Linux 7 with multi-screen Zaphod mode configurations, which are uncommon in modern environments but may persist in certain industrial or specialized use cases.

The primary impact of CVE-2023-5380 is denial of service due to X server crashes in affected Red Hat Enterprise Linux 7 systems configured with legacy multi-screen Zaphod mode. For European organizations, this could disrupt operations relying on graphical user interfaces in specialized environments such as industrial control systems, research labs, or legacy application setups that have not migrated to newer graphical server configurations. While the vulnerability does not compromise confidentiality or integrity, the availability impact could lead to productivity loss, operational delays, or interruption of critical services. Given the complexity and specificity of the exploit conditions, widespread impact is unlikely; however, organizations with legacy multi-screen setups should be cautious. The lack of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation. The medium severity rating reflects the limited scope and difficulty of exploitation but acknowledges the potential operational disruption in affected environments.

To mitigate CVE-2023-5380, organizations should first identify any systems running Red Hat Enterprise Linux 7 with multi-screen configurations using Zaphod mode. Since this is a legacy and uncommon setup, auditing graphical server configurations is critical. Avoid using Zaphod mode if possible, or reconfigure to single-screen or standard multi-screen modes that do not involve multiple protocol screens. Monitor Red Hat security advisories closely for patches addressing this vulnerability and apply updates promptly once available. In environments where patching is delayed, consider restricting local access to trusted users only, as exploitation requires local low-privilege access. Additionally, implement system monitoring to detect unusual X server crashes that could indicate attempted exploitation. For critical systems, consider migrating to newer Red Hat Enterprise Linux versions or alternative graphical server implementations that do not exhibit this vulnerability. Document and test any configuration changes in controlled environments before deployment to avoid unintended service disruptions.