CVE-2024-1086 is a use-after-free vulnerability categorized under CWE-416 found in the Linux kernel's netfilter subsystem, specifically within the nf_tables component. The vulnerability stems from the nft_verdict_init() function allowing positive values as drop errors within the hook verdict, which causes the nf_hook_slow() function to mishandle these values. When NF_DROP is issued with a drop error that resembles NF_ACCEPT, this leads to a double free condition. This memory corruption flaw can be exploited by a local attacker to escalate privileges, potentially gaining root access. The vulnerability affects Linux kernel versions starting from 3.15 and was publicly disclosed on January 31, 2024. The CVSS v3.1 base score is 7.8, indicating high severity with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, meaning the attack requires local access with low complexity and privileges but no user interaction, and can impact confidentiality, integrity, and availability significantly. No public exploits have been reported yet, but the nature of the vulnerability makes it a critical concern for systems relying on vulnerable kernel versions. The recommended mitigation is to upgrade the kernel to versions including or beyond the commit f342de4e2f33e0e39165d8639387aa6c19dff660, which addresses the issue by correcting the handling of hook verdicts and preventing the double free. Organizations should also review local user permissions and monitor for suspicious local activity that could indicate exploitation attempts.

The impact of CVE-2024-1086 on European organizations can be significant, especially for those relying on Linux-based servers and infrastructure. Successful exploitation allows a local attacker to escalate privileges to root, potentially leading to full system compromise. This can result in unauthorized access to sensitive data, disruption of critical services, and the ability to deploy further attacks such as ransomware or data exfiltration. Given the widespread use of Linux in enterprise environments, cloud infrastructure, and critical sectors like finance, telecommunications, and government, the vulnerability poses a high risk. The requirement for local access limits remote exploitation but does not eliminate risk, as attackers may leverage other vulnerabilities or social engineering to gain initial footholds. The vulnerability also threatens the integrity and availability of systems, potentially causing service outages or corruption of data. European organizations must prioritize patching to maintain compliance with data protection regulations and avoid operational disruptions.

1. Upgrade Linux kernels to versions including or beyond the commit f342de4e2f33e0e39165d8639387aa6c19dff660 where the vulnerability is fixed. 2. Implement strict local user access controls and limit the number of users with shell or local access privileges to reduce the attack surface. 3. Employ kernel integrity monitoring tools to detect anomalous behavior indicative of exploitation attempts. 4. Regularly audit and monitor system logs for unusual activity related to netfilter or nf_tables components. 5. Use containerization or sandboxing to isolate critical applications and limit the impact of potential privilege escalations. 6. Coordinate with Linux distribution vendors to receive timely security updates and advisories. 7. For environments where immediate patching is not feasible, consider disabling or restricting netfilter nf_tables functionality if it is not essential. 8. Conduct internal penetration testing to validate the effectiveness of mitigations and detect potential exploitation paths.