CVE-2016-3396 in Windows
Summary
by MITRE
Graphics Device Interface (aka GDI or GDI+) in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows Server 2012 Gold and R2; Windows RT 8.1; Windows 10 Gold, 1511, and 1607; Office 2007 SP3; Office 2010 SP2; Word Viewer; Skype for Business 2016; Lync 2013 SP1; Lync 2010; Lync 2010 Attendee; and Live Meeting 2007 Console allows remote attackers to execute arbitrary code via a crafted embedded font, aka "GDI+ Remote Code Execution Vulnerability."
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 09/23/2022
The CVE-2016-3396 vulnerability represents a critical remote code execution flaw within the Graphics Device Interface plus component of Microsoft Windows operating systems and Office applications. This vulnerability specifically targets the GDI+ subsystem which handles graphics rendering operations and font processing within the Windows ecosystem. The flaw manifests when the system processes specially crafted embedded fonts, allowing malicious actors to execute arbitrary code with the privileges of the targeted user. The vulnerability affects a broad range of Microsoft products including various Windows versions from Vista through Windows 10, along with Office 2007 through 2016, Word Viewer, Skype for Business, Lync, and Live Meeting applications. This extensive scope makes the vulnerability particularly dangerous as it can be exploited across multiple platforms and application contexts. The vulnerability is categorized under CWE-121, which describes heap-based buffer overflow conditions that occur when a program writes data past the end of a heap-allocated buffer. This classification aligns with the nature of the flaw where font processing routines fail to properly validate buffer boundaries during embedded font handling operations.
The technical exploitation of this vulnerability occurs through the manipulation of font files embedded within documents or applications. When a user opens a maliciously crafted document containing an embedded font, the GDI+ subsystem processes the font data without adequate input validation, leading to memory corruption. This memory corruption can be leveraged to overwrite critical memory locations, ultimately allowing attackers to inject and execute malicious code within the context of the affected application. The attack vector is particularly insidious because it can be delivered through email attachments, web downloads, or any medium that allows document execution. The vulnerability's exploitation requires minimal user interaction, often just opening a malicious document, making it particularly effective for phishing campaigns and social engineering attacks. According to ATT&CK framework, this vulnerability maps to T1203, which describes the execution of malicious code through the manipulation of system components, and T1059, which covers the use of scripting languages to execute commands. The attack chain typically involves initial compromise through document delivery followed by privilege escalation and persistence mechanisms.
The operational impact of CVE-2016-3396 is severe and multifaceted across enterprise environments. Organizations running affected Windows versions and Office applications face significant risk of unauthorized code execution, data theft, and system compromise. The vulnerability can be exploited to establish backdoors, deploy malware, or conduct advanced persistent threats that may go undetected for extended periods. The broad compatibility of the vulnerability across multiple Microsoft products means that traditional security measures may not provide adequate protection, as the attack can occur through various application vectors. Network administrators must consider the potential for lateral movement once an initial compromise occurs, as attackers can use the executed code to pivot to other systems within the network. The vulnerability also impacts organizations with legacy systems, as Windows Server 2008 and Office 2007/2010 versions remain in use despite their end-of-life status, making these systems particularly vulnerable to exploitation. The financial impact includes potential data breaches, regulatory fines, system recovery costs, and business disruption. Security teams must implement immediate mitigation strategies including patch deployment, application whitelisting, and network segmentation to reduce the attack surface. Additionally, user education regarding suspicious document attachments becomes crucial in preventing successful exploitation attempts. Microsoft's security response included issuing patches for all affected versions, but organizations with delayed patch deployment or legacy systems remain at elevated risk of exploitation. The vulnerability underscores the importance of maintaining current security patches and implementing layered defense strategies to protect against sophisticated attack vectors that target core system components like graphics rendering engines.