CVE-2021-28455 in Windows
Summary
by MITRE • 05/12/2021
Microsoft Jet Red Database Engine and Access Connectivity Engine Remote Code Execution Vulnerability
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Analysis
by VulDB Data Team • 05/13/2021
The CVE-2021-28455 vulnerability represents a critical remote code execution flaw within Microsoft Jet Red Database Engine and Access Connectivity Engine components. This vulnerability stems from improper handling of specially crafted database files that can be processed by these engine components. The flaw exists in how the engines parse and interpret specific data structures within database files, creating opportunities for malicious actors to execute arbitrary code on affected systems. The vulnerability affects multiple Microsoft products including Office applications, Access databases, and various database connectivity components that rely on these engines for data processing and manipulation.
The technical implementation of this vulnerability involves memory corruption issues that occur during the parsing of malformed database records. Attackers can craft malicious database files that trigger buffer overflows or other memory handling errors when processed by the affected engines. These memory corruption conditions can be exploited to overwrite critical memory locations, potentially allowing attackers to inject and execute malicious code with the privileges of the targeted user. The vulnerability is particularly concerning because it can be triggered through legitimate database file processing operations, making it difficult to distinguish between benign and malicious database content at runtime. The flaw is categorized under CWE-121 as a stack-based buffer overflow, which is a well-known class of vulnerabilities that has been extensively documented in cybersecurity literature.
Operationally, this vulnerability poses significant risks to enterprise environments where Microsoft Office and Access applications are commonly used for data management and business operations. The remote execution capability means that attackers can exploit this vulnerability through email attachments, web downloads, or network file shares without requiring local system access. This makes the attack surface particularly broad and increases the likelihood of successful exploitation in typical business environments. Organizations running older versions of Microsoft Office or those that have not applied the relevant security patches are particularly vulnerable to this attack vector. The vulnerability can be leveraged for privilege escalation attacks, data exfiltration, and establishing persistent access to compromised systems, making it a serious concern for information security teams.
Mitigation strategies for CVE-2021-28455 should prioritize immediate deployment of Microsoft security patches and updates. Organizations must ensure that all affected systems receive the relevant cumulative updates that address this specific vulnerability. Additional protective measures include implementing strict file validation policies, particularly for database files received from external sources, and deploying application whitelisting solutions to prevent execution of untrusted database files. Network segmentation and monitoring solutions should be employed to detect anomalous database processing activities that might indicate exploitation attempts. Security teams should also consider disabling unnecessary database connectivity features and implementing sandboxing techniques for database file processing operations. The mitigation approach aligns with ATT&CK technique T1203, which focuses on exploitation of remote services, and emphasizes the importance of maintaining up-to-date system patches as a primary defense mechanism. Regular security assessments and vulnerability scanning should be conducted to identify any systems that may have been compromised or remain unpatched, ensuring comprehensive protection against this and similar remote code execution vulnerabilities.