CVE-2017-0285 in Windows
Summary
by MITRE
Uniscribe in 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, 1607, 1703, Windows Server 2016, Microsoft Office 2007 SP3, Microsoft Office 2010 SP2, and Microsoft Office Word Viewer allows improper disclosure of memory contents, aka "Windows Uniscribe Information Disclosure Vulnerability". This CVE ID is unique from CVE-2017-0282, CVE-2017-0284, and CVE-2017-8534.
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Analysis
by VulDB Data Team • 12/28/2020
The Windows Uniscribe information disclosure vulnerability represents a critical memory corruption flaw within Microsoft's text processing subsystem that affects multiple operating systems and office applications. This vulnerability resides in the Uniscribe engine responsible for complex text layout and rendering operations, particularly when handling Unicode text with specific font configurations and text formatting sequences. The flaw manifests when the system processes certain text inputs that trigger improper memory handling within the Uniscribe component, leading to potential information disclosure through memory contents that should remain protected. The vulnerability impacts a wide range of Microsoft products including 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 versions from Gold through 1703, Windows Server 2016, along with various Microsoft Office products from 2007 SP3 through 2010 SP2 and Word Viewer.
The technical implementation of this vulnerability involves improper handling of memory buffers during text processing operations where the Uniscribe engine fails to properly validate input parameters before accessing memory locations. This flaw falls under the CWE-125 vulnerability category, which describes out-of-bounds read conditions that can result in information disclosure, and aligns with ATT&CK technique T1059.007 for process injection and T1550.002 for use of stolen credentials. When malicious actors exploit this vulnerability, they can potentially read memory contents from adjacent memory locations, potentially exposing sensitive data such as encryption keys, passwords, or other confidential information stored in memory. The attack typically requires a user to view or process specially crafted text content that triggers the vulnerable code path within Uniscribe, making this a user-initiated information disclosure vulnerability rather than a remote code execution threat.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can provide attackers with sufficient sensitive data to facilitate more sophisticated attacks including credential theft, privilege escalation, or targeted exploitation of other system components. The widespread affected platforms mean that organizations running these legacy systems face significant risk, particularly in enterprise environments where older Windows versions and Office products remain in use. Security professionals must consider that this vulnerability can be leveraged as a stepping stone for more advanced attacks, as the leaked memory contents might include pointers to system functions, stack addresses, or other information that could aid in bypassing security mitigations like ASLR. The vulnerability's classification as a memory disclosure issue means that even without direct code execution capabilities, attackers can gather intelligence that significantly weakens overall system security posture.
Organizations should prioritize immediate patching of affected systems through Microsoft's security updates, particularly focusing on the Windows 7, Windows Server 2008 R2, and Office 2010 SP2 installations where the vulnerability is most prevalent. Additionally, implementing network segmentation and access controls can help limit potential exploitation paths, while monitoring for unusual text processing activities may aid in detecting attempted exploitation. Security teams should also consider disabling unnecessary text rendering features and implementing application whitelisting policies to prevent execution of potentially malicious documents. The vulnerability demonstrates the importance of maintaining up-to-date security patches across all system components, as the affected Uniscribe engine has been superseded by newer text rendering technologies in subsequent Windows versions, making the patching process essential for maintaining baseline security defenses against information disclosure threats.