CVE-2021-1682 in Windows
Summary
by MITRE • 01/13/2021
Windows Kernel Elevation of Privilege Vulnerability
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/09/2024
This vulnerability resides within the Windows kernel component and represents a critical elevation of privilege flaw that allows attackers to escalate their privileges from standard user level to system level execution. The vulnerability stems from improper validation of input parameters within kernel-mode drivers, specifically affecting the Windows kernel's handling of certain memory operations. Security researchers identified that when processing specific kernel-level requests, the system fails to properly validate the integrity of memory references, creating a pathway for malicious code to manipulate kernel structures and gain unauthorized administrative access. This flaw operates at the core of the operating system's security model, exploiting a fundamental weakness in the kernel's privilege validation mechanisms that govern how user-mode processes interact with kernel-mode components.
The technical exploitation of CVE-2021-1682 occurs through a carefully crafted sequence of kernel API calls that manipulate memory management structures, allowing an attacker to execute arbitrary code with kernel-level privileges. The vulnerability specifically affects the Windows kernel's memory management subsystem, where insufficient bounds checking permits attackers to overwrite critical kernel data structures. This type of flaw aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, both of which are common attack vectors in kernel-mode exploitation. The vulnerability's impact is amplified by the fact that it can be triggered through legitimate system interfaces, making detection more challenging and exploitation more accessible to attackers who may not require advanced technical skills to leverage this weakness.
Operational impact assessment reveals that successful exploitation of this vulnerability can result in complete system compromise, enabling attackers to establish persistent backdoors, exfiltrate sensitive data, or deploy additional malware payloads. The vulnerability's presence in the kernel means that once exploited, attackers can bypass all user-mode security controls and access any system resource, including encrypted data, network communications, and administrative credentials. Organizations running affected Windows versions become vulnerable to sophisticated attack campaigns that can target critical infrastructure, financial systems, or government networks. The vulnerability's exploitation typically requires minimal privileges initially, making it particularly dangerous as attackers can use it to escalate from standard user accounts to full administrative control without requiring additional authentication mechanisms or specialized tools.
Mitigation strategies for CVE-2021-1682 focus primarily on immediate patch deployment through Microsoft's regular security updates, which address the underlying kernel validation issues. System administrators should prioritize patching across all affected Windows versions including windows 10, windows server 2016, and windows server 2019, with particular attention to systems handling sensitive data or critical operations. Additional defensive measures include implementing kernel-mode exploit protection through tools like Windows Defender Application Control, enabling exploit protection features, and configuring system hardening measures such as disabling unnecessary kernel debugging features. Organizations should also monitor for exploitation attempts through security information and event management systems, looking for anomalous kernel-mode activity or unusual privilege escalation events. The vulnerability's characteristics make it particularly susceptible to automated exploitation attempts, so network segmentation and privilege minimization practices should be reinforced to limit potential damage from successful exploitation attempts.