CVE-2019-1023 is an information disclosure vulnerability found in Microsoft ChakraCore, the JavaScript engine used by Microsoft Edge. The vulnerability arises from improper handling of objects in memory by the scripting engine, which can lead to leakage of sensitive information. An attacker exploiting this flaw could obtain information from the memory space of the browser process, potentially enabling further compromise of the user's system. The attack vector is web-based: an attacker can host a malicious website or inject crafted content into compromised or user-content-accepting websites to trigger the vulnerability. However, exploitation requires user interaction, such as convincing the user to click a link leading to the malicious content. The vulnerability does not allow direct code execution or system control but can disclose confidential data, which may be leveraged in subsequent attacks. Microsoft addressed this issue by modifying how ChakraCore handles objects in memory to prevent information leakage. The CVSS v3.1 base score is 6.5 (medium severity), reflecting the network attack vector, no privileges required, user interaction needed, and high impact on confidentiality but no impact on integrity or availability. No known exploits in the wild have been reported, and the vulnerability affects versions of ChakraCore prior to the patch released in June 2019.

For European organizations, this vulnerability poses a moderate risk primarily related to confidentiality breaches. Since ChakraCore is integral to Microsoft Edge, organizations using Edge browsers are potentially exposed. Information disclosure could lead to leakage of sensitive corporate data or user credentials, which attackers might use for lateral movement or privilege escalation within networks. Sectors with high reliance on web applications and sensitive data, such as finance, healthcare, and government, could be particularly impacted. The requirement for user interaction reduces the likelihood of widespread automated exploitation but does not eliminate targeted phishing or social engineering attacks. Additionally, organizations with strict data protection regulations under GDPR must consider the implications of any data leakage incidents. While the vulnerability does not directly compromise system integrity or availability, the indirect consequences of information disclosure could lead to more severe attacks if combined with other vulnerabilities or social engineering tactics.

European organizations should ensure that all systems running Microsoft Edge or ChakraCore are updated with the latest security patches released by Microsoft since June 2019. Specifically, deploying the security update that addresses CVE-2019-1023 is critical. Network security teams should monitor for phishing campaigns or suspicious links that could be used to lure users to malicious sites exploiting this vulnerability. Implementing robust email filtering and user awareness training focused on recognizing social engineering attempts can reduce the risk of user interaction exploitation. Additionally, organizations should consider application whitelisting or browser isolation technologies to limit exposure to malicious web content. Employing endpoint detection and response (EDR) solutions capable of detecting anomalous memory access patterns may help identify exploitation attempts. Finally, organizations should review and enforce strict browser security configurations, disable unnecessary scripting features where possible, and maintain comprehensive logging to facilitate incident investigation if exploitation is suspected.