CVE-2020-1247 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory, aka 'Win32k Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-1207, CVE-2020-1251, CVE-2020-1253, CVE-2020-1310.
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Analysis
by VulDB Data Team • 10/23/2020
The vulnerability described in CVE-2020-1247 represents a critical elevation of privilege flaw within the Windows operating system that specifically impacts the Windows kernel-mode driver component. This weakness resides in the win32k.sys driver which serves as the foundation for Windows graphical user interface operations and handles critical system resources. The vulnerability stems from improper handling of objects in memory, creating a pathway for malicious actors to escalate their privileges from standard user level to SYSTEM level access. This particular flaw is distinct from several other related vulnerabilities including CVE-2020-1207, CVE-2020-1251, CVE-2020-1253, and CVE-2020-1310, each addressing different aspects of the Windows kernel security model but sharing the common theme of memory management vulnerabilities.
The technical implementation of this vulnerability involves a memory corruption issue within the win32k.sys driver that processes user-mode requests for graphical operations. When legitimate system calls are made to manipulate window objects, the driver fails to properly validate or sanitize memory references, potentially allowing an attacker to craft malicious input that triggers buffer overflows or use-after-free conditions. This flaw operates at the kernel level where the privilege separation between user mode and kernel mode is typically enforced, making it particularly dangerous as it can bypass standard security boundaries. The vulnerability's exploitation typically requires an attacker to first gain initial access to a system, often through social engineering or other attack vectors, before leveraging this kernel-level weakness to achieve full system compromise.
From an operational impact perspective, successful exploitation of CVE-2020-1247 can result in complete system compromise with the ability to execute arbitrary code at the highest privilege level. Attackers can leverage this vulnerability to install persistent backdoors, extract sensitive data, modify system configurations, or establish covert communication channels. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments. Organizations running these affected systems face significant risk of data breaches, lateral movement within networks, and potential establishment of persistent threats that can remain undetected for extended periods. The vulnerability's exploitation can occur through various attack vectors including malicious email attachments, compromised websites, or drive-by downloads that trigger the vulnerable code path.
Security professionals should implement multiple layers of defense to protect against exploitation of this vulnerability. The most critical mitigation involves applying the official Microsoft security patches released as part of the patch Tuesday updates for the affected period. Additionally, implementing application whitelisting policies can prevent unauthorized executables from running and reduce the attack surface. Network segmentation and monitoring solutions should be deployed to detect anomalous behavior that might indicate exploitation attempts. The vulnerability aligns with several ATT&CK framework techniques including privilege escalation through kernel exploits and persistence mechanisms. Organizations should also consider implementing exploit prevention technologies such as Control Flow Guard and Address Space Layout Randomization to make exploitation more difficult. Regular security assessments and vulnerability scanning should be conducted to identify systems that may not have received the necessary patches, as this vulnerability has been actively exploited in the wild. The underlying CWE classification for this issue falls under CWE-121, which specifically addresses stack-based buffer overflow conditions that can lead to privilege escalation attacks.