CVE-2021-1943 in Snapdragon Auto
Summary
by MITRE • 07/13/2021
Possible buffer out of bound read can occur due to improper validation of TBTT count and length while parsing the beacon response in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Wired Infrastructure and Networking
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Analysis
by VulDB Data Team • 07/16/2021
This vulnerability resides in the wireless networking stack of various Qualcomm Snapdragon chipsets, specifically within the beacon response parsing functionality that handles timing beacon transmission parameters. The issue manifests as a potential buffer out-of-bounds read condition when processing the Timing Beacon Transmission Time (TBTT) count and length fields during beacon frame parsing operations. The flaw occurs in the firmware or driver components responsible for managing wireless communication protocols, particularly affecting devices that utilize 802.11 wireless standards for connectivity. When a malformed beacon frame is received with invalid TBTT count or length values, the parsing routine fails to properly validate these parameters before attempting to access memory locations, potentially leading to unauthorized memory reads beyond allocated buffer boundaries. This vulnerability affects a broad range of Snapdragon product lines including automotive systems, mobile devices, industrial internet of things deployments, and networking infrastructure equipment. The improper validation mechanism allows attackers to craft malicious beacon frames that exploit the buffer overflow condition, potentially enabling information disclosure or system instability.
The technical implementation of this vulnerability stems from inadequate input validation within the wireless frame parsing logic, specifically in how the system processes the TBTT parameters that define timing synchronization points in wireless networks. The flaw can be categorized under CWE-125 as an out-of-bounds read condition, where the system attempts to read memory beyond the allocated buffer boundaries. When parsing beacon frames, the system does not adequately verify that the TBTT count and length values fall within expected ranges before using these values to calculate memory offsets or buffer indices. This allows attackers to manipulate these parameters in beacon frames to cause the parsing routine to access invalid memory locations, potentially reading sensitive data from adjacent memory regions or causing system crashes. The vulnerability is particularly concerning because beacon frames are commonly transmitted in wireless networks and can be easily spoofed by adversaries within range of the target device. The parsing routines operate at kernel level or privileged execution contexts, making successful exploitation potentially more impactful than typical user-space vulnerabilities.
Operational impact of this vulnerability extends across multiple domains of wireless networking and device connectivity. In automotive applications using Snapdragon Auto chipsets, this flaw could potentially compromise vehicle communication systems and wireless infotainment networks, especially during critical timing-sensitive operations. Mobile devices and industrial IoT deployments face similar risks where unauthorized memory access could expose sensitive operational data or disrupt critical connectivity functions. The vulnerability enables potential attackers to perform reconnaissance activities by reading adjacent memory contents, which might contain encryption keys, authentication tokens, or other sensitive information. Additionally, the out-of-bounds read condition could cause system crashes or unexpected behavior in wireless communication modules, leading to service disruptions or denial of connectivity. Network infrastructure equipment using Snapdragon wired infrastructure and networking chipsets could experience stability issues when processing malformed beacon frames from compromised or malicious network nodes. The attack surface is broad due to the widespread deployment of these chipsets across various device categories, making this vulnerability particularly concerning for organizations managing large wireless network deployments.
Mitigation strategies for this vulnerability should focus on firmware and software updates provided by Qualcomm and device manufacturers, which typically include proper input validation mechanisms for beacon frame parsing operations. Organizations should implement network monitoring solutions to detect and alert on anomalous beacon frame patterns that might indicate exploitation attempts. Device administrators should ensure timely application of security patches and firmware updates to address the root cause of the buffer validation issue. Network segmentation and access controls can help limit the potential impact by restricting wireless access to critical systems. Implementing wireless intrusion detection systems that monitor beacon frame parameters and identify malformed frames can provide additional defense-in-depth measures. Security teams should also consider disabling unnecessary wireless functionality on devices where it is not required, reducing the attack surface. The vulnerability aligns with several ATT&CK techniques including T1059 for command and control communication and T1046 for network service scanning, as attackers might use this vulnerability to establish persistent wireless communication channels or probe network configurations. Regular security assessments of wireless network infrastructure should include testing for similar buffer overflow conditions in other wireless protocol implementations to prevent similar vulnerabilities from being exploited.