CVE-2017-8477 in Windows
Summary
by MITRE
Microsoft Windows 7 SP1, Windows Server 2008 SP2 and R2 SP1, Windows 8.1 and Windows RT 8.1, Windows Server 2012 and R2, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016 allow an authenticated attacker to run a specially crafted application when the Windows kernel improperly initializes objects in memory, aka "Win32k Information Disclosure Vulnerability". This CVE ID is unique from CVE-2017-8470, CVE-2017-8471, CVE-2017-8472, CVE-2017-8473, CVE-2017-8475, and CVE-2017-8484.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/28/2020
The vulnerability identified as CVE-2017-8477 represents a critical information disclosure flaw within the Windows kernel's handling of object initialization processes. This vulnerability specifically affects multiple Windows operating system versions including Windows 7 SP1 through Windows 10 version 1703, along with their respective server counterparts. The issue stems from improper memory management during kernel object initialization, creating a scenario where authenticated attackers can exploit this weakness to gain unauthorized access to sensitive information. The vulnerability operates within the Win32k.sys kernel driver component, which manages user-mode graphics interfaces and system-level window operations, making it particularly dangerous as it resides at the core of Windows graphical subsystem functionality.
The technical exploitation of this vulnerability occurs when the Windows kernel fails to properly initialize objects in memory before they are accessed, leading to information disclosure through memory corruption. Attackers can craft malicious applications that trigger this improper initialization sequence, potentially allowing them to read sensitive kernel memory locations and extract confidential data. This type of vulnerability falls under CWE-125, which describes out-of-bounds read conditions, and is classified as a privilege escalation vector that can be leveraged for information gathering and further attack development. The flaw exists in the kernel-mode component of Windows, specifically within the win32k.sys driver that handles user interface elements and graphics operations, making it a prime target for attackers seeking to escalate privileges and access system resources.
The operational impact of CVE-2017-8477 extends beyond simple information disclosure, as it provides attackers with a foothold for more sophisticated attacks within the Windows environment. An authenticated attacker with limited system access can potentially exploit this vulnerability to read kernel memory contents, which may include sensitive data such as encryption keys, credential information, or other confidential system data. This information can then be used to facilitate additional attacks including credential theft, privilege escalation, or lateral movement within the network. The vulnerability's presence in multiple Windows versions across different product lines increases its attack surface significantly, as it affects both client and server operating systems, making it particularly attractive to threat actors seeking broad exploitation capabilities. The vulnerability also aligns with ATT&CK technique T1059.001, which involves the use of command and scripting interpreter for execution, as attackers can leverage the information disclosure to gather system intelligence for more targeted attacks.
Mitigation strategies for CVE-2017-8477 should focus on immediate patch deployment through Microsoft's regular security updates, as the vendor has released patches addressing this specific vulnerability. Organizations should prioritize updating all affected Windows systems to prevent exploitation attempts, particularly those running the vulnerable operating system versions. Additional protective measures include implementing strict access controls to limit authenticated user privileges, monitoring for suspicious process activity related to graphics operations, and employing network segmentation to contain potential exploitation attempts. Security teams should also consider deploying endpoint protection solutions that can detect anomalous behavior patterns associated with kernel exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date system patches and implementing defense-in-depth strategies, as the information disclosure aspect of this vulnerability can serve as a precursor to more severe security incidents. Organizations should also conduct regular vulnerability assessments to identify systems running affected software versions and ensure comprehensive coverage of all Windows endpoints within their network infrastructure.