CVE-2016-0141 in Office
Summary
by MITRE
The Visual Basic macros in Microsoft Office 2007 SP3, 2010 SP2, 2013 SP1, and 2016 export a certificate-store private key during a document-save operation, which allows attackers to obtain sensitive information via unspecified vectors, aka "Microsoft Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 09/16/2022
The vulnerability described in CVE-2016-0141 represents a critical information disclosure flaw within Microsoft Office's Visual Basic macro processing functionality. This issue affects multiple versions of Microsoft Office including 2007 SP3, 2010 SP2, 2013 SP1, and 2016, making it a widespread concern across the Office ecosystem. The vulnerability stems from the improper handling of certificate stores during document save operations, specifically when Visual Basic macros are present in Office documents. This flaw allows attackers to extract private keys from the certificate store, potentially compromising the security of encrypted communications and digital signatures that rely on these cryptographic materials.
The technical nature of this vulnerability lies in the export mechanism that occurs when Office documents containing Visual Basic macros are saved to disk. During this save operation, the system inadvertently exposes private key material from the certificate store, creating an information disclosure channel that attackers can exploit. This behavior violates fundamental security principles of key management and cryptographic protection, as private keys should never be accessible through normal document operations. The vulnerability operates at the application level within Microsoft Office, specifically targeting the macro execution environment where certificate handling occurs during document persistence.
The operational impact of CVE-2016-0141 extends beyond simple information disclosure, as compromised private keys can enable sophisticated attacks including man-in-the-middle operations, certificate forgery, and impersonation of legitimate systems. Attackers who successfully exploit this vulnerability could potentially decrypt sensitive communications, forge digital signatures, or impersonate trusted entities within the organization's network. The unspecified vectors mentioned in the vulnerability description suggest that attackers could leverage various attack paths including malicious Office documents delivered via email, removable media, or web-based attacks. This makes the vulnerability particularly dangerous as it can be exploited through multiple delivery mechanisms, increasing the attack surface and potential impact.
Organizations should implement immediate mitigations including disabling macro execution in Office applications, particularly when processing documents from untrusted sources. Security controls should focus on restricting certificate store access during document save operations and implementing strict macro security policies. The vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a classic case of improper information handling within application security. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access and privilege escalation, as compromised private keys can be used to gain deeper access to systems and networks. Additionally, the vulnerability demonstrates the importance of secure coding practices and proper cryptographic implementation, particularly in enterprise applications that handle sensitive data and security credentials.