CVE-2022-49419 is a high-severity use-after-free vulnerability in the Linux kernel's framebuffer device (fbdev) subsystem, specifically within the vesafb driver. The issue arises from improper handling of the fb_info structure's lifecycle during driver removal and framebuffer unregistration. The vulnerability stems from a race condition between the .fb_destroy and .remove callbacks. Initially, a patch intended to fix a use-after-free by moving the fb_info cleanup from the .remove handler to the .fb_destroy callback did not consider the scenario where .fb_destroy is called before .remove. In such cases, unregister_framebuffer() frees the fb_info structure, but vesafb_remove() subsequently accesses this freed pointer, leading to a use-after-free condition (CWE-416). This flaw can be exploited locally by a user with limited privileges (PR:L) without requiring user interaction (UI:N). The vulnerability impacts confidentiality, integrity, and availability (C:H/I:H/A:H) because exploitation could allow an attacker to execute arbitrary code within kernel context, potentially leading to privilege escalation or system crashes. The affected versions include specific Linux kernel commits prior to the fix. Although no known exploits are currently reported in the wild, the vulnerability's nature and CVSS score of 7.8 indicate a significant risk if weaponized. The technical fix involves reordering operations to ensure that the fb_info pointer is accessed before it is freed, preventing invalid memory access.

For European organizations, this vulnerability poses a substantial risk, especially for those relying on Linux-based systems with framebuffer devices enabled, such as embedded systems, servers, and workstations using the vesafb driver. Exploitation could lead to local privilege escalation, allowing attackers to gain root access, compromise system integrity, and disrupt availability through kernel panics or denial of service. This is particularly critical for sectors with stringent security requirements like finance, healthcare, critical infrastructure, and government agencies. The vulnerability could also be leveraged as a stepping stone for lateral movement within networks. Given the widespread use of Linux in European enterprises and public sector institutions, unpatched systems could be targeted by attackers aiming to exploit this flaw to gain persistent and privileged access.

Organizations should promptly apply the official Linux kernel patches that address CVE-2022-49419. Specifically, updating to kernel versions that include the fix moving the fb_info pointer access before unregister_framebuffer() is essential. For environments where immediate patching is not feasible, consider disabling the vesafb driver if it is not required, or restricting access to framebuffer devices to trusted users only. Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), and enable security modules like SELinux or AppArmor to limit the impact of potential exploitation. Regularly audit systems for outdated kernel versions and monitor for unusual local activity that could indicate exploitation attempts. Additionally, incorporate this vulnerability into vulnerability management and patching workflows to ensure timely remediation.