CVE-2021-40424 in Secure Anywhere
Summary
by MITRE • 04/15/2022
An out-of-bounds read vulnerability exists in the IOCTL GetProcessCommand and B_03 of Webroot Secure Anywhere 21.4. A specially-crafted executable can lead to denial of service. An attacker can issue an ioctl to trigger this vulnerability. An out-of-bounds read vulnerability exists in the IOCTL GetProcessCommand and B_03 of Webroot Secure Anywhere 21.4. The GetProcessCommandLine IOCTL request could cause an out-of-bounds read in the device driver WRCore_x64. An attacker can issue an ioctl to trigger this vulnerability.
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Analysis
by VulDB Data Team • 04/20/2022
The vulnerability identified as CVE-2021-40424 represents a critical out-of-bounds read flaw within the Webroot Secure Anywhere 21.4 security solution, specifically affecting the kernel-mode device driver WRCore_x64. This issue manifests through two distinct IOCTL interfaces: GetProcessCommand and B_03, both of which are designed to interact with running processes and system command lines. The vulnerability stems from inadequate input validation and memory boundary checking within the driver's handling of these specific IOCTL requests, creating a scenario where malicious input can cause the driver to access memory locations beyond the intended buffer boundaries.
The technical exploitation of this vulnerability occurs through the manipulation of IOCTL (Input/Output Control) commands issued to the Webroot kernel driver. When an attacker crafts a specially-crafted executable that sends malformed IOCTL requests to the WRCore_x64 driver, the driver's insufficient bounds checking allows it to read memory beyond the allocated buffer space. This out-of-bounds memory access typically results in system instability and can lead to a complete system crash or denial of service condition. The vulnerability is particularly concerning because it operates at the kernel level where privilege escalation is not required for exploitation, making it accessible to any user-level process that can interact with the vulnerable driver interface.
From an operational security perspective, this vulnerability creates significant risk for systems running Webroot Secure Anywhere 21.4, as it can be leveraged to cause persistent denial of service attacks against critical systems. The impact extends beyond simple service disruption since the kernel-level nature of the vulnerability means that system stability is compromised, potentially leading to complete system crashes that require manual intervention for recovery. The vulnerability also represents a potential vector for more sophisticated attacks, as the out-of-bounds read could potentially expose sensitive kernel memory contents to an attacker. According to CWE classification, this vulnerability maps to CWE-125: Out-of-bounds Read, which is a well-documented weakness in software security that occurs when software reads data past the end of a valid buffer.
The attack surface for this vulnerability is limited to systems running the specific version of Webroot Secure Anywhere 21.4 where the vulnerable driver components remain active and accessible. However, the implications are severe as the vulnerability can be triggered through legitimate user interaction with the system, making it difficult to detect and prevent. Organizations should consider implementing immediate mitigations such as disabling the vulnerable driver components, applying vendor patches once available, or implementing network-level controls to restrict access to the IOCTL interfaces. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and system compromise through kernel-level vulnerabilities, potentially enabling adversaries to establish persistent access or escalate their privileges within the affected systems. The vulnerability demonstrates the critical importance of proper input validation and memory management in kernel-mode drivers, as even seemingly benign operations can create significant security risks when proper boundary checking is not implemented.