CVE-2018-8392 in Windows
Summary
by MITRE
A buffer overflow vulnerability exists in the Microsoft JET Database Engine that could allow remote code execution on an affected system, 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 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8393.
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Analysis
by VulDB Data Team • 05/08/2023
The vulnerability identified as CVE-2018-8392 represents a critical buffer overflow flaw within Microsoft's JET Database Engine, a component that has been integral to various Windows operating systems since the early 2000s. This database engine serves as the foundation for numerous applications including Microsoft Access, Outlook, and various third-party software solutions that rely on the .mdb file format for data storage and retrieval. The flaw manifests when the engine processes malformed or specially crafted database files, particularly those with maliciously constructed headers or data structures that exceed allocated buffer boundaries. The vulnerability affects a broad spectrum of Microsoft operating systems including Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, and Windows 10 Servers, indicating the widespread impact of this particular flaw across the Windows ecosystem.
The technical nature of this buffer overflow vulnerability stems from inadequate input validation within the JET Database Engine's parsing routines. When processing database files, the engine allocates fixed-size buffers to store data structures and metadata, but fails to properly verify that incoming data fits within these boundaries. This allows attackers to craft malicious database files that deliberately overflow these buffers, potentially overwriting adjacent memory locations with malicious code or corrupting critical program execution flow. The vulnerability specifically relates to how the engine handles certain field types and data formatting within database records, particularly when processing compound data structures or when encountering malformed field definitions that cause the parsing logic to write beyond allocated memory regions. The flaw is classified under CWE-121 as a stack-based buffer overflow, which can lead to arbitrary code execution when the overflow corrupts return addresses or other critical execution pointers. This type of vulnerability is particularly dangerous because it can be triggered through legitimate database file processing operations, making it difficult to distinguish between benign and malicious file access patterns.
The operational impact of this vulnerability extends far beyond simple data corruption, as it provides attackers with a pathway for remote code execution on vulnerable systems. An attacker could potentially deliver a malicious database file through various attack vectors including email attachments, web downloads, or even through compromised websites that serve malicious content to unsuspecting users. When a user opens or processes the malicious database file, either manually or through automated processes such as Outlook's email attachment handling or application auto-opening features, the buffer overflow occurs and can result in complete system compromise. The vulnerability is particularly concerning because it can be exploited without requiring user interaction beyond opening the file, as the JET engine processes database files automatically during normal application operations. Attackers could leverage this vulnerability to establish persistent backdoors, escalate privileges, or deploy additional malware payloads, making it a prime target for advanced persistent threat actors and ransomware groups. The impact is further amplified by the fact that many applications and services rely on the JET database engine for their data storage needs, creating multiple potential attack surfaces.
Mitigation strategies for CVE-2018-8392 require a multi-layered approach combining immediate patch management with defensive security measures. Microsoft released security updates that address this vulnerability through patches that correct the buffer overflow conditions in the JET Database Engine, and organizations should prioritize applying these patches as quickly as possible. However, in environments where patching may be delayed or restricted, defensive measures such as restricting database file handling capabilities, implementing application whitelisting policies, and configuring email security solutions to block suspicious database file attachments can provide additional protection. Network-based defenses including firewalls and intrusion detection systems can be configured to monitor for suspicious database file transfers or access patterns, while endpoint protection solutions should be updated to include signatures for detecting exploitation attempts. The vulnerability's classification under ATT&CK technique T1059.005 for command and scripting interpreter and T1068 for exploit for privilege escalation highlights the need for comprehensive monitoring of system calls and process execution patterns. Organizations should also implement proper file validation procedures and restrict the execution of database files from untrusted sources, particularly those that might be encountered through web browsing or email interactions. Regular security assessments and vulnerability scanning should be conducted to identify any remaining systems that might still be exposed to this vulnerability, ensuring that the entire attack surface is properly protected against exploitation attempts.