CVE-2016-3235 in Office
Summary
by MITRE
Microsoft Visio 2007 SP3, Visio 2010 SP2, Visio 2013 SP1, Visio 2016, Visio Viewer 2007 SP3, and Visio Viewer 2010 mishandle library loading, which allows local users to gain privileges via a crafted application, aka "Microsoft Office OLE DLL Side Loading Vulnerability."
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Analysis
by VulDB Data Team • 04/23/2026
The vulnerability identified as CVE-2016-3235 represents a critical privilege escalation flaw within Microsoft Visio and Visio Viewer applications across multiple versions. This issue stems from improper handling of library loading mechanisms during the execution of Office OLE (Object Linking and Embedding) operations, creating an exploitable condition that allows local attackers to elevate their system privileges through carefully crafted malicious applications.
The technical flaw manifests in the way these Visio applications process dynamic link libraries during OLE operations, specifically through a vulnerability categorized under CWE-427 Uncontrolled Search Path Element. When Visio applications encounter OLE objects, they traverse search paths to locate required DLL files without proper validation of the library sources, enabling attackers to place malicious DLLs in strategic locations that the applications will load automatically. This behavior directly aligns with the ATT&CK technique T1574.001 for DLL Side-Loading, where legitimate applications are tricked into loading attacker-controlled code.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with elevated system access that could enable further exploitation within the compromised environment. Local users who can execute code on the target system can leverage this vulnerability to gain higher privileges, potentially allowing them to install malicious software, modify system configurations, or access sensitive data. The attack vector requires local system access but does not necessitate network connectivity, making it particularly concerning for environments where physical access or initial compromise is possible.
Mitigation strategies for CVE-2016-3235 should focus on both immediate patching and operational security measures. Microsoft released security updates addressing this vulnerability through regular security patches, and organizations should prioritize applying these updates to all affected Visio installations. Additionally, implementing application whitelisting policies that restrict which DLLs can be loaded by Visio applications can provide defense-in-depth protection. System administrators should also consider disabling OLE automation features when possible and monitoring for unusual DLL loading patterns through endpoint detection and response solutions. The vulnerability highlights the importance of proper library loading security practices and demonstrates how seemingly minor implementation flaws in application loading mechanisms can create significant security risks.