CVE-2024-38055 is an information disclosure vulnerability identified in the Microsoft Windows Codecs Library component of Windows 10 Version 1809 (build 10.0.17763.0). The root cause is improper input validation (CWE-20), which means the software fails to correctly verify or sanitize input data before processing it. This flaw can be exploited by a local attacker with low privileges (PR:L) to gain unauthorized access to sensitive information stored or processed by the Codecs Library. The attack does not require user interaction (UI:N) and does not affect system integrity or availability, focusing solely on confidentiality (C:H, I:N, A:N). The attack vector is local (AV:L), meaning the attacker must have some level of access to the target system, such as a logged-in user or through another local compromise. The vulnerability has a CVSS v3.1 base score of 5.5, categorized as medium severity, reflecting moderate risk due to the local attack vector and limited scope of impact. No known exploits have been reported in the wild, and no official patches have been linked at the time of publication, though Microsoft is expected to release updates. This vulnerability is particularly relevant for organizations still operating legacy Windows 10 versions, as newer versions may have addressed this issue. The improper input validation could allow attackers to craft malicious codec data or files that, when processed by the vulnerable library, leak sensitive information such as memory contents or other protected data. This could facilitate further attacks or data breaches if exploited successfully.

For European organizations, the primary impact of CVE-2024-38055 is the potential unauthorized disclosure of sensitive information on systems running Windows 10 Version 1809. This could include leakage of confidential business data, user credentials, or other protected information processed by the Codecs Library. Although the vulnerability does not allow code execution or system disruption, information disclosure can aid attackers in reconnaissance or subsequent attacks. Organizations in sectors such as government, finance, healthcare, and critical infrastructure that maintain legacy Windows 10 systems are at higher risk. The local attack vector limits remote exploitation, but insider threats or attackers with initial footholds could leverage this vulnerability to escalate information gathering. The lack of user interaction requirement means exploitation can occur stealthily once local access is obtained. Given that Windows 10 Version 1809 is an older release, many organizations may have already migrated to newer versions, but those that have not remain exposed. The absence of known exploits reduces immediate risk, but the medium severity rating and potential for sensitive data leakage warrant proactive mitigation.

1. Upgrade affected systems from Windows 10 Version 1809 to a supported and fully patched Windows version, such as Windows 10 21H2 or later, or Windows 11, to eliminate the vulnerability. 2. If upgrading is not immediately feasible, implement strict access controls to limit local user privileges and prevent unauthorized local access to vulnerable systems. 3. Monitor internal systems for unusual local activity that could indicate attempts to exploit this vulnerability, including suspicious file processing or codec usage. 4. Apply any security updates or patches released by Microsoft as soon as they become available for Windows 10 Version 1809. 5. Employ endpoint detection and response (EDR) tools to detect anomalous behavior related to codec processing or information disclosure attempts. 6. Educate users about the risks of running outdated operating systems and encourage timely updates. 7. Conduct regular audits of systems to identify legacy Windows 10 installations and prioritize their remediation. 8. Use application whitelisting and restrict execution of untrusted files that could trigger the vulnerable codec processing.