Researchers at Morphisec have uncovered a critical zero-click remote code execution (RCE) vulnerability in Microsoft Outlook, identified as CVE-2024-38021. This flaw is particularly dangerous because it does not require user authentication and can be exploited without any interaction from the user, especially when emails are received from trusted sources. This makes it a significant threat as it could lead to data breaches, unauthorized access, and other malicious activities.
Unlike a previously disclosed vulnerability, CVE-2024-30103, CVE-2024-38021 can be exploited without user interaction when emails come from trusted senders. Morphisec has urged Microsoft to reclassify the vulnerability as “Critical” due to its potential for widespread impact, despite Microsoft initially rating it as “Important.” While exploiting this vulnerability might be complex, it could become more feasible if combined with other vulnerabilities, increasing the risk of severe attacks.
Morphisec reported the vulnerability to Microsoft on April 21, 2024, and Microsoft confirmed it five days later. A patch was released on July 9, 2024, as part of Microsoft’s Patch Tuesday updates. The zero-click nature of this vulnerability for trusted senders, combined with the absence of authentication requirements, heightens the risk of unauthorized access and arbitrary code execution.
To mitigate the risks associated with CVE-2024-38021, it is recommended that users promptly apply the latest patches for Microsoft Outlook and Office applications. Enhancing email security, such as disabling automatic email previews, and educating users about the dangers of opening emails from unknown sources are also crucial. Microsoft’s swift response is noted, but the vulnerability’s severity should be reassessed to ensure adequate attention and protection measures.
