CVE-2022-21123 is a medium-severity vulnerability affecting certain Intel processors, stemming from incomplete cleanup of multi-core shared buffers. Specifically, this flaw allows an authenticated local user to potentially disclose sensitive information by exploiting residual data left in shared buffers that are not properly cleared between context switches or core usage. The vulnerability arises because the processor's internal mechanisms that manage shared buffers across multiple cores fail to fully sanitize data, enabling an attacker with local access and limited privileges to read information that should be inaccessible. This type of vulnerability falls under CWE-459, which relates to incomplete cleanup, and can lead to confidentiality breaches without impacting data integrity or system availability. The CVSS 3.1 base score is 5.5, reflecting a medium risk level, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), requiring privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and no availability impact (A:N). No known exploits are currently reported in the wild, and no patches were linked in the provided data, suggesting that mitigation may rely on firmware or microcode updates from Intel or system vendors. This vulnerability is particularly relevant in multi-user or multi-tenant environments where local users share the same physical hardware, such as in virtualized servers or shared workstations, as it could allow unauthorized access to sensitive data from other processes or users on the same machine.

For European organizations, the primary impact of CVE-2022-21123 lies in potential confidentiality breaches within environments using affected Intel processors. Enterprises relying on multi-core Intel CPUs in data centers, cloud infrastructure, or corporate workstations may face risks of sensitive data leakage between users or processes. This is especially critical for sectors handling sensitive personal data under GDPR, such as finance, healthcare, and government agencies. The vulnerability requires local authenticated access, which somewhat limits remote exploitation but does not eliminate insider threats or risks from compromised accounts. In virtualized or containerized environments common in European cloud providers and enterprises, this flaw could enable cross-tenant data leakage, undermining data isolation guarantees. Although no integrity or availability impacts are noted, the confidentiality breach potential could lead to regulatory penalties, reputational damage, and loss of intellectual property. The absence of known exploits reduces immediate risk, but the medium severity and the widespread use of Intel processors in Europe necessitate proactive mitigation to prevent future exploitation.

To mitigate CVE-2022-21123 effectively, European organizations should: 1) Monitor Intel and OEM vendor advisories closely for firmware or microcode updates addressing this vulnerability and apply them promptly. 2) Implement strict access controls to limit local user privileges and reduce the number of users with authenticated local access to critical systems. 3) Employ hardware-based isolation techniques such as Intel VT-x or AMD-V virtualization extensions combined with updated hypervisors that may include mitigations for shared buffer cleanup issues. 4) Use endpoint detection and response (EDR) tools to monitor for suspicious local activity indicative of attempts to exploit shared buffer data leakage. 5) In multi-tenant cloud or virtualized environments, enforce strong tenant isolation policies and consider workload placement strategies that minimize risk from co-residency on vulnerable hardware. 6) Conduct regular security audits and penetration tests focusing on local privilege escalation and information disclosure vectors. 7) Educate system administrators and users about the risks of local access vulnerabilities and enforce policies to prevent unauthorized physical or logical access to sensitive systems.