CVE-2020-26652 in rtl8812au
Summary
by MITRE • 08/22/2023
An issue was discovered in function nl80211_send_chandef in rtl8812au v5.6.4.2 allows attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 10/03/2024
The vulnerability identified as CVE-2020-26652 resides within the nl80211_send_chandef function of the rtl8812au driver version 5.6.4.2, representing a critical denial of service flaw that can be exploited by remote attackers. This issue specifically affects wireless network drivers used in Linux-based systems, where the rtl8812au driver is commonly deployed for USB wireless adapters supporting 802.11ac and 802.11n standards. The vulnerability manifests when the driver processes channel definition information through the nl80211 interface, which is part of the Linux kernel's wireless subsystem designed to manage wireless devices and their configuration parameters.
The technical flaw stems from insufficient input validation within the nl80211_send_chandef function, which fails to properly sanitize channel definition parameters received from userspace applications or network packets. When malformed or excessively large channel definition structures are passed to this function, the driver does not perform adequate bounds checking or parameter validation, leading to potential buffer overflows or memory corruption scenarios. This weakness allows attackers to craft malicious channel configuration data that, when processed by the vulnerable driver, triggers kernel memory corruption or infinite loops that result in system instability and complete denial of service for the wireless networking functionality.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the overall system stability and availability of wireless connectivity in affected devices. Systems utilizing the rtl8812au driver, particularly those in enterprise environments, industrial control systems, or embedded devices with wireless capabilities, face significant risk when this vulnerability is exploited. The denial of service can occur both remotely through network-based attacks and locally through privilege escalation scenarios, making it particularly dangerous in multi-user environments where attackers might gain access to wireless configuration interfaces. This vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1499.004 for network denial of service attacks.
Mitigation strategies for CVE-2020-26652 should prioritize immediate driver updates from the vendor or kernel maintainers, as the most effective solution involves patching the vulnerable code to implement proper input validation and bounds checking. Administrators should also consider implementing network segmentation and access controls to limit exposure of wireless interfaces to untrusted networks, while monitoring for unusual wireless configuration changes that might indicate exploitation attempts. Additionally, system administrators should ensure that wireless drivers are regularly updated as part of their overall patch management procedures, particularly in environments where wireless connectivity is critical for operations. The vulnerability highlights the importance of proper input validation in kernel drivers and the potential for remote exploitation of wireless subsystem components, making it essential for organizations to maintain current security practices and vulnerability assessments for all wireless networking infrastructure components.