CVE-2017-11832 in Windows
Summary
by MITRE
The Microsoft Windows embedded OpenType (EOT) font engine in Windows 7 SP1, Windows Server 2008 SP2 and 2008 R2 SP1, and Windows Server 2012 allows an attacker to potentially read data that was not intended to be disclosed, due to the way that the Microsoft Windows EOT font engine parses specially crafted embedded fonts, aka "Windows EOT Font Engine Information Disclosure Vulnerability." This CVE ID is unique from CVE-2017-11835.
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Analysis
by VulDB Data Team • 01/23/2021
The vulnerability identified as CVE-2017-11832 represents a critical information disclosure flaw within the Microsoft Windows embedded OpenType EOT font engine. This vulnerability specifically affects Windows 7 SP1, Windows Server 2008 SP2 and 2008 R2 SP1, as well as Windows Server 2012 systems. The flaw exists in how the Windows EOT font engine processes specially crafted embedded fonts, creating an avenue for unauthorized data exposure. The vulnerability falls under the Common Weakness Enumeration category CWE-200, which deals with information exposure, and specifically relates to improper access control mechanisms in font processing components. The technical nature of this vulnerability stems from insufficient validation and boundary checking within the font parsing logic, allowing attackers to manipulate font structures in ways that can potentially reveal sensitive memory contents.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially expose system memory contents that may include sensitive data such as cryptographic keys, user credentials, or application memory structures. Attackers can exploit this vulnerability by crafting malicious EOT font files that, when processed by the vulnerable Windows systems, trigger memory access patterns that leak information to unauthorized parties. This type of attack aligns with the MITRE ATT&CK framework's technique T1059, which covers command and script interpreter execution, as attackers may leverage this information disclosure to gather intelligence for more sophisticated attacks. The vulnerability's exploitation requires minimal privileges and can be executed through various attack vectors including email attachments, web downloads, or malicious websites, making it particularly dangerous in enterprise environments where font rendering is frequently encountered.
Mitigation strategies for CVE-2017-11832 should include immediate deployment of Microsoft security updates and patches, which address the font parsing logic flaws in the EOT engine. Organizations should also implement network segmentation and access controls to limit exposure, particularly in environments where users may encounter untrusted font content. The vulnerability demonstrates the importance of secure coding practices in font processing components and highlights the need for robust input validation and memory safety mechanisms. Security teams should monitor for indicators of compromise related to font-related attacks and consider implementing application whitelisting policies that restrict execution of potentially malicious font files. Additionally, regular security assessments of font handling components and adherence to Microsoft's security best practices can help prevent exploitation of similar vulnerabilities in the future, as this flaw represents a classic example of how seemingly benign components like font engines can become attack vectors in modern cybersecurity landscapes.