CVE-2024-20660 is a security vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) that involves an out-of-bounds read condition within the Microsoft Message Queuing (MSMQ) component. This vulnerability is classified under CWE-125, which pertains to out-of-bounds read errors where a program reads data past the boundary of a buffer. Specifically, MSMQ is a messaging protocol that allows applications running on separate servers/processes to communicate asynchronously. The vulnerability could allow an attacker with low privileges (PR:L) to remotely exploit the flaw without user interaction (UI:N) over a network (AV:N). The CVSS v3.1 base score is 6.5, indicating a medium severity level, with a high impact on confidentiality (C:H) but no impact on integrity or availability. The vulnerability does not require user interaction and has low attack complexity (AC:L). The scope remains unchanged (S:U), meaning the exploit affects only the vulnerable component without impacting other system components. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability could potentially allow an attacker to read sensitive information from memory buffers, leading to information disclosure. Given the nature of MSMQ, this could expose sensitive inter-process or inter-server communication data, potentially leaking credentials, configuration details, or other sensitive information stored in memory buffers. The vulnerability was reserved in late November 2023 and published in January 2024, indicating recent discovery and disclosure. Since it affects Windows 10 Version 1809, which is an older but still in-use version of Windows 10, systems that have not been updated or migrated to newer versions remain at risk.

For European organizations, the impact of CVE-2024-20660 could be significant, especially for those relying on legacy Windows 10 Version 1809 systems running MSMQ for critical messaging infrastructure. Information disclosure vulnerabilities can lead to leakage of sensitive data such as internal communications, authentication tokens, or configuration parameters, which could be leveraged for further attacks like privilege escalation or lateral movement within networks. Sectors such as finance, healthcare, government, and critical infrastructure that often use MSMQ for reliable messaging might face increased risk. The confidentiality breach could undermine compliance with GDPR and other data protection regulations, potentially leading to legal and reputational consequences. Since the vulnerability can be exploited remotely without user interaction, attackers could target exposed MSMQ services over the network, increasing the attack surface. However, the medium severity and requirement for low privileges somewhat limit the immediate risk, but the absence of patches and known exploits means organizations must proactively address the issue to prevent future exploitation.

European organizations should prioritize the following mitigation steps: 1) Identify and inventory all systems running Windows 10 Version 1809 with MSMQ enabled. 2) Apply any forthcoming security patches from Microsoft as soon as they are released; monitor official Microsoft security advisories closely. 3) If patching is not immediately possible, consider disabling MSMQ on affected systems where it is not critical to operations to reduce the attack surface. 4) Restrict network access to MSMQ services using firewall rules or network segmentation, allowing only trusted hosts and minimizing exposure to untrusted networks. 5) Implement strict access controls and monitoring on systems running MSMQ to detect unusual activity indicative of exploitation attempts. 6) Upgrade legacy systems to supported Windows versions that have received security updates to reduce exposure to this and other vulnerabilities. 7) Conduct regular security assessments and penetration testing focused on MSMQ and related messaging infrastructure to identify potential weaknesses. 8) Educate IT and security teams about this vulnerability and ensure incident response plans include scenarios involving MSMQ exploitation.