CVE-2021-1965 in Snapdragon Auto
Summary
by MITRE • 07/13/2021
Possible buffer overflow due to lack of parameter length check during MBSSID scan IE parse in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Mobile, Snapdragon Wired Infrastructure and Networking
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Analysis
by VulDB Data Team • 07/16/2021
This vulnerability represents a critical buffer overflow condition that occurs during the parsing of MBSSID scan information elements within Qualcomm Snapdragon automotive and mobile platform components. The flaw exists in the absence of proper parameter length validation during the processing of beacon or probe response frames that contain multiple BSSIDs. When a maliciously crafted beacon frame is transmitted with oversized or malformed MBSSID information elements, the parsing routine fails to validate the incoming data length before copying it into fixed-size buffers. This fundamental lack of input validation creates a predictable buffer overflow condition that can be exploited by remote attackers within the wireless network coverage area. The vulnerability affects multiple Snapdragon product lines including automotive systems, mobile devices, compute platforms, connectivity solutions, and networking infrastructure components, indicating a widespread impact across Qualcomm's ecosystem. According to CWE-121, this represents a classic stack-based buffer overflow due to insufficient bounds checking, while the ATT&CK framework categorizes this under T1059.007 for application execution and T1566 for credential access through network-based attacks.
The technical implementation of this vulnerability stems from the wireless protocol parsing logic that processes 802.11 management frames containing multiple BSSID information elements. During normal operation, wireless devices scan for available networks by parsing beacon frames from neighboring access points. The MBSSID (Multiple BSSID) feature allows a single access point to advertise multiple BSSIDs within a single beacon frame, enabling load balancing and network optimization. However, the parsing routine does not validate that the length parameter specified in the information element matches the actual data size, allowing an attacker to craft a frame with a declared length that exceeds the buffer capacity. This mismatch enables an attacker to overwrite adjacent memory locations with controlled data, potentially leading to arbitrary code execution or system crashes. The vulnerability is particularly concerning in automotive applications where Snapdragon Auto platforms control critical vehicle functions, as it could enable remote code execution on vehicle infotainment systems or even affect vehicle safety-critical components.
The operational impact of this vulnerability extends across multiple threat scenarios and attack vectors. An attacker positioned within wireless network range could exploit this vulnerability by transmitting specially crafted beacon frames that trigger the buffer overflow condition when victim devices attempt to parse the malformed information elements. This attack could result in denial of service conditions where devices become unresponsive or crash, or more critically, enable remote code execution that allows attackers to gain persistent access to the affected systems. In automotive contexts, this could potentially compromise vehicle security systems, infotainment networks, or even communication with external vehicle services. The vulnerability affects both consumer and industrial deployments, making it particularly dangerous for connected vehicle ecosystems where wireless communication is essential. The lack of parameter length validation means that the attack surface is broad and can be triggered through normal wireless scanning operations without requiring special privileges or physical access to the target device.
Mitigation strategies for this vulnerability should focus on both immediate defensive measures and long-term architectural improvements. Qualcomm has issued patches for affected Snapdragon platforms that implement proper length validation during MBSSID information element parsing, ensuring that declared lengths match actual data sizes before buffer operations occur. Organizations should prioritize applying these firmware and software updates across all affected devices, particularly automotive systems and critical infrastructure components. Network administrators should implement monitoring solutions to detect unusual beacon frame patterns that may indicate exploitation attempts, while also considering network segmentation to limit the potential impact of successful attacks. The solution aligns with security best practices outlined in NIST SP 800-115 for vulnerability management and follows CWE recommendations for preventing buffer overflow conditions through proper input validation. Additionally, implementing robust network access controls and wireless intrusion detection systems can provide additional layers of defense against exploitation attempts. Device manufacturers should incorporate more rigorous testing procedures for wireless protocol parsing components, including fuzz testing and boundary condition validation, to prevent similar vulnerabilities from emerging in future releases.