CVE-2024-30031 is a high-severity elevation of privilege vulnerability affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability is classified as a Use After Free (CWE-416) issue within the Windows Cryptography Next Generation (CNG) Key Isolation Service. This service is responsible for managing cryptographic keys and performing cryptographic operations in a secure isolated environment. The vulnerability arises when the service improperly handles memory, leading to a use-after-free condition. This flaw can be exploited by an attacker with limited privileges (low-level privileges) who has local access to the system. Exploiting this vulnerability does not require user interaction, but it does require the attacker to have local access and the ability to execute code with low privileges. The vulnerability has a CVSS 3.1 base score of 7.8, indicating a high severity level. The CVSS vector indicates that the attack vector is local (AV:L), the attack complexity is high (AC:H), privileges required are low (PR:L), no user interaction is needed (UI:N), and the scope is changed (S:C). The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning a successful exploit could allow an attacker to fully compromise the affected system, gaining elevated privileges and potentially executing arbitrary code or manipulating cryptographic keys. No known exploits are currently reported in the wild, and no patches are linked yet, indicating that mitigation may rely on vendor updates or workarounds once available. The vulnerability affects a specific legacy Windows 10 version (1809), which is still in use in some environments but is no longer the latest Windows 10 release. Given the critical role of the CNG Key Isolation Service in securing cryptographic operations, this vulnerability poses a significant risk to system security and trustworthiness.

For European organizations, the impact of CVE-2024-30031 can be substantial, especially for those still running Windows 10 Version 1809 in production environments. The vulnerability allows local attackers with limited privileges to escalate their privileges to SYSTEM level, potentially gaining full control over affected machines. This can lead to unauthorized access to sensitive data, manipulation or theft of cryptographic keys, and disruption of critical services relying on Windows cryptographic functions. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk due to their reliance on cryptographic security and the potential regulatory consequences of data breaches. The high impact on confidentiality, integrity, and availability means that exploitation could result in data breaches, loss of data integrity, and system downtime. Since the vulnerability requires local access, insider threats or attackers who have already compromised lower-privileged accounts could leverage this flaw to deepen their foothold. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits rapidly after disclosure. The changed scope in the CVSS vector indicates that exploitation could affect components beyond the initially vulnerable service, potentially impacting the entire system security posture.

1. Immediate mitigation should focus on upgrading affected systems to a supported and fully patched version of Windows 10 or later, as Windows 10 Version 1809 is legacy and may no longer receive security updates. 2. If upgrading is not immediately feasible, restrict local access to affected systems by enforcing strict access controls, including limiting physical and remote access to trusted personnel only. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities that could indicate exploitation attempts. 4. Regularly audit and review user privileges to minimize the number of accounts with local access and low privileges that could be leveraged for exploitation. 5. Monitor security advisories from Microsoft for the release of patches or workarounds specific to this vulnerability and apply them promptly once available. 6. Implement network segmentation to isolate critical systems running legacy Windows versions from less secure network segments. 7. Conduct user training to raise awareness about the risks of local privilege escalation and insider threats. 8. Use enhanced logging and alerting on cryptographic service activities to detect anomalous behavior that could indicate exploitation attempts.