CVE-2018-8423 in Windows
Summary
by MITRE
A remote code execution vulnerability exists in the Microsoft JET Database Engine, aka "Microsoft JET Database Engine Remote Code Execution Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2019, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
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Analysis
by VulDB Data Team • 05/23/2023
The vulnerability CVE-2018-8423 represents a critical remote code execution flaw within Microsoft's JET Database Engine, a component that has been integral to Windows operating systems since Windows 95. This database engine serves as the foundation for various Microsoft applications including Access, Outlook, and numerous third-party software solutions that rely on JET for data storage and retrieval. The vulnerability stems from improper input validation within the engine's handling of specially crafted database files, creating a condition where maliciously formatted data can trigger arbitrary code execution when processed by vulnerable systems. The JET Database Engine operates at a low level within the Windows ecosystem, making it an attractive target for attackers seeking to establish persistent access to compromised systems. This vulnerability affects a broad range of Windows operating systems spanning multiple versions including legacy platforms like Windows Server 2008 and Windows Server 2008 R2, alongside modern releases such as Windows 10 and Windows Server 2019, demonstrating the widespread impact of the flaw.
The technical exploitation of this vulnerability occurs through a buffer overflow condition in the JET Database Engine when processing malformed database records. Attackers can craft malicious database files that, when opened or accessed by vulnerable applications, cause the engine to execute malicious code with the privileges of the user who opened the file. The flaw specifically manifests when the engine attempts to parse corrupted or specially constructed database headers, leading to memory corruption that can be leveraged to execute arbitrary instructions. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and aligns with ATT&CK technique T1203, involving legitimate user execution of malicious code. The vulnerability is particularly dangerous because it can be triggered through various attack vectors including email attachments, web downloads, or network shares, making it suitable for both targeted attacks and mass exploitation campaigns.
The operational impact of CVE-2018-8423 extends beyond simple remote code execution, as it provides attackers with a pathway to establish persistent access and potentially escalate privileges within compromised environments. Once successfully exploited, attackers can deploy additional malware, establish backdoors, or use the compromised system as a launch point for further network infiltration. The vulnerability's prevalence across multiple Windows versions means that organizations with diverse IT environments face significant exposure, as legacy systems often lack the security updates that newer releases receive. Security researchers have noted that the vulnerability is particularly concerning because it can be exploited without user interaction in certain scenarios, making it suitable for automated attack campaigns. The JET Database Engine's widespread use in enterprise applications means that a single compromised system can potentially lead to broader network infiltration, as the vulnerability affects not just individual user machines but also server environments where database operations are critical.
Organizations should implement immediate mitigation strategies including applying the Microsoft security patches released in August 2018 as part of the security update cycle. System administrators should prioritize patching all affected Windows versions, particularly focusing on legacy systems that may not receive regular updates. Network segmentation and application whitelisting can help limit the potential impact of exploitation by preventing unauthorized database file access. The vulnerability's characteristics make it suitable for exploitation through phishing campaigns, where attackers send malicious database files as email attachments. Monitoring network traffic for suspicious database file access patterns and implementing strict file type validation can help detect potential exploitation attempts. Organizations should also consider disabling unnecessary database functionality and restricting user permissions to minimize the potential damage from successful exploitation. The remediation process should include thorough vulnerability assessments across all systems to identify any remaining unpatched instances, as well as implementing security awareness training to reduce the risk of social engineering attacks that could leverage this vulnerability.