CVE-2021-38692 in QVR Elite
Summary
by MITRE • 01/14/2022
A stack buffer overflow vulnerability has been reported to affect QNAP device running QVR Elite, QVR Pro, QVR Guard. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of QVR Elite, QVR Pro, QVR Guard: QuTS hero h5.0.0: QVR Elite 2.1.4.0 (2021/12/06) and later QuTS hero h4.5.4: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 5.0.0: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 4.5.4: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 4.5.4: QVR Pro 2.1.3.0 (2021/12/06) and later QTS 5.0.0: QVR Pro 2.1.3.0 (2021/12/06) and later QTS 4.5.4: QVR Guard 2.1.3.0 (2021/12/06) and later QTS 5.0.0: QVR Guard 2.1.3.0 (2021/12/06) and later
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Analysis
by VulDB Data Team • 01/17/2022
This stack buffer overflow vulnerability affects QNAP devices running QVR Elite, QVR Pro, and QVR Guard software components, representing a critical security weakness that could enable remote code execution attacks. The vulnerability stems from improper input validation within the affected software, allowing attackers to craft malicious payloads that exceed the allocated buffer space and overwrite adjacent memory locations. Such buffer overflows typically occur when programs fail to properly check the length of input data before copying it into fixed-size memory buffers, creating opportunities for attackers to manipulate program execution flow through carefully crafted inputs that trigger the overflow condition.
The technical flaw manifests when legitimate users or attackers provide input data that exceeds the predefined buffer limits within the QNAP QVR software implementations. This condition creates a situation where adjacent memory regions become overwritten, potentially corrupting critical program data, stack canaries, return addresses, or other execution metadata. When exploited successfully, this vulnerability allows attackers to execute arbitrary code with the privileges of the affected process, which typically runs with elevated permissions due to the nature of surveillance and video recording software. The attack vector likely involves network-based exploitation through protocols used by QVR software for device communication, configuration management, or data transfer operations.
The operational impact of this vulnerability extends beyond simple code execution capabilities, as it represents a significant threat to enterprise security infrastructure and surveillance systems. Organizations relying on QNAP QVR solutions for video monitoring and security operations face potential compromise of their entire security ecosystem, including unauthorized access to live video feeds, modification of recorded data, and potential lateral movement within network environments. The vulnerability affects multiple QNAP QVR variants across different firmware versions, indicating a widespread exposure that requires immediate attention from system administrators. Attackers could leverage this weakness to establish persistent backdoors, conduct data exfiltration, or disrupt critical surveillance operations that depend on these systems for security monitoring.
The affected QNAP QVR products operate within the cybersecurity domain classified under CWE-121 Stack-based Buffer Overflow, which is a well-documented weakness in software development practices that directly maps to the ATT&CK technique T1059.007 Command and Scripting Interpreter: PowerShell. Organizations should implement immediate mitigation strategies including firmware updates to the patched versions mentioned in the advisory, network segmentation to isolate affected devices, and monitoring for suspicious network traffic patterns. Additionally, security teams should conduct comprehensive vulnerability assessments of their QNAP device deployments, implement network intrusion detection systems to monitor for exploitation attempts, and establish incident response procedures specifically tailored to address potential compromise of surveillance infrastructure. The vulnerability highlights the importance of proper input validation and memory management practices in security-critical applications, particularly those handling sensitive data in enterprise environments where the consequences of exploitation could be severe.