CVE-2021-21792 in Advanced SystemCare Ultimate
Summary
by MITRE • 08/06/2021
An information disclosure vulnerability exists in the the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O read requests. A specially crafted I/O request packet (IRP) can lead to privileged reads in the context of a driver which can result in sensitive information disclosure from the kernel. The IN instruction can read four bytes from the given I/O device, potentially leaking sensitive device data to unprivileged users.
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Analysis
by VulDB Data Team • 08/09/2021
The vulnerability identified as CVE-2021-21792 represents a critical information disclosure flaw within IOBit Advanced SystemCare Ultimate version 14.2.0.220, specifically within its driver component that handles privileged I/O read operations. This vulnerability stems from improper validation and handling of Input/Output Request Packets (IRPs) that are processed in kernel context, creating an avenue for unauthorized data access. The flaw manifests when the driver fails to adequately validate I/O requests, allowing maliciously crafted IRPs to bypass normal security boundaries and execute privileged operations that should only be accessible to system-level processes. The vulnerability directly impacts the kernel's integrity by enabling unprivileged users to perform operations that normally require elevated privileges, thereby undermining the fundamental security model of the operating system.
The technical implementation of this vulnerability leverages the IN instruction capability within the driver's I/O handling mechanism, which allows reading four bytes of data from specified I/O ports. This particular implementation creates a direct pathway for information leakage since the driver does not properly enforce access controls or validate the origin and legitimacy of I/O requests. The IN instruction, when executed in kernel context, can access hardware registers and device memory that typically should remain protected from user-mode applications. This flaw aligns with CWE-200, which addresses "Information Exposure," and specifically relates to improper restriction of operations within a recognized security boundary. The vulnerability essentially creates a privilege escalation vector where user-level processes can manipulate kernel-level I/O operations to extract sensitive information from hardware devices, potentially including cryptographic keys, system configuration data, or other confidential device parameters.
The operational impact of CVE-2021-21792 extends beyond simple information disclosure to encompass potential system compromise and data breach scenarios. Attackers who exploit this vulnerability can extract sensitive kernel memory contents, device-specific configuration data, or proprietary information that may be stored in hardware registers. This information leakage could enable further attacks, including but not limited to, credential harvesting, system fingerprinting, or targeted exploitation of other system components. The vulnerability's persistence in the kernel driver means that successful exploitation would remain effective across system reboots until patched, providing attackers with sustained access to sensitive information. Additionally, the vulnerability's nature makes it particularly dangerous in enterprise environments where system integrity is paramount, as it could potentially allow attackers to gain insights into system architecture, device configurations, and security implementations that would normally be protected.
Mitigation strategies for CVE-2021-21792 must address both immediate remediation and long-term security hardening measures. The primary and most effective mitigation involves applying the official patch provided by IOBit for Advanced SystemCare Ultimate version 14.2.0.220, which corrects the improper I/O request validation and strengthens the driver's privilege enforcement mechanisms. System administrators should also implement additional security controls including kernel-mode driver signature enforcement, application whitelisting, and regular security audits of installed drivers. From an ATT&CK framework perspective, this vulnerability relates to techniques such as T1068 (Exploitation for Privilege Escalation) and T1552 (Unsecured Credentials), as it enables attackers to escalate privileges and access sensitive system information. Organizations should also consider implementing monitoring solutions that can detect anomalous I/O operations or attempts to access restricted hardware registers, as these activities may indicate exploitation attempts. Furthermore, maintaining up-to-date security tools and ensuring comprehensive driver security assessments can help prevent similar vulnerabilities from being introduced into system environments, particularly given the widespread use of third-party system optimization software that often requires elevated privileges to function properly.