CVE-2016-0183 in Office
Summary
by MITRE
The Windows font library in Microsoft Office 2010 SP2, Word 2010 SP2, Word Automation Services on SharePoint Server 2010 SP2, and Office Web Apps 2010 SP2 allows remote attackers to execute arbitrary code via a crafted embedded font, aka "Microsoft Office Graphics RCE Vulnerability."
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Analysis
by VulDB Data Team • 08/18/2022
The vulnerability identified as CVE-2016-0183 represents a critical remote code execution flaw within the Windows font library component of Microsoft Office products. This vulnerability specifically affects Microsoft Office 2010 SP2, Word 2010 SP2, Word Automation Services on SharePoint Server 2010 SP2, and Office Web Apps 2010 SP2 installations. The flaw resides in how these applications process embedded font files, creating a pathway for malicious actors to execute arbitrary code on affected systems. The vulnerability operates through a crafted embedded font that, when processed by the vulnerable Office applications, triggers a memory corruption condition that can be exploited to gain unauthorized access and execute malicious payloads.
The technical nature of this vulnerability stems from improper input validation within the font processing engine of Microsoft Office applications. When these applications encounter a specially crafted embedded font file, the font library fails to properly validate the font structure and data, leading to buffer overflow conditions or other memory corruption issues. This class of vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The vulnerability demonstrates characteristics consistent with the attack pattern described in the MITRE ATT&CK framework under technique T1059.005 for command and scripting interpreter, as successful exploitation would enable attackers to execute commands on the target system. The flaw specifically affects the graphics rendering capabilities of Office applications, where embedded fonts are processed as part of document rendering operations, making it particularly dangerous in document-based attack scenarios.
The operational impact of CVE-2016-0183 extends beyond simple remote code execution to encompass significant security risks for enterprise environments. Attackers can leverage this vulnerability to deploy malware, establish persistent backdoors, or escalate privileges within compromised systems. The vulnerability's exploitation typically occurs through social engineering campaigns where users open malicious documents containing the crafted embedded font, making it particularly effective in phishing attacks. Organizations using older versions of Microsoft Office 2010 SP2 are especially vulnerable as these products have reached end-of-life support, leaving them without security updates or patches. The attack surface is broad since the vulnerability affects multiple Microsoft Office products and services, including SharePoint integration capabilities, making it a prime target for attackers seeking to compromise enterprise document management systems.
Mitigation strategies for CVE-2016-0183 should focus on immediate protective measures given the vulnerability's severity and the lack of available patches for affected products. Organizations should implement strict document filtering policies that prevent the opening of documents containing embedded fonts from untrusted sources. Network-level protections including firewall rules that block access to potentially malicious domains and content filtering solutions can help reduce exposure. The most effective long-term solution involves upgrading to supported versions of Microsoft Office that include security patches addressing this vulnerability. Microsoft released updates for newer Office versions that remediate this issue, though the affected Office 2010 SP2 products have no official patches available. Security teams should also consider implementing application whitelisting policies and sandboxing techniques to limit the potential impact of successful exploitation attempts, particularly in environments where immediate upgrades are not feasible. Additionally, regular security awareness training for users can help reduce the risk of successful social engineering attacks that leverage this vulnerability.