CVE-2021-1920 in Snapdragon Auto
Summary
by MITRE • 09/08/2021
Integer underflow can occur due to improper handling of incoming RTCP packets in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon IoT, Snapdragon Voice & Music, Snapdragon Wearables
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 09/11/2021
The vulnerability identified as CVE-2021-1920 represents a critical integer underflow condition within the Real-Time Control Protocol processing subsystem of various Qualcomm Snapdragon chipsets. This flaw manifests when the system receives malformed RTCP packets, which are typically used for monitoring transmission quality and providing feedback in real-time communication applications. The improper handling of packet data structures leads to arithmetic overflow conditions that can result in unpredictable system behavior and potential security implications.
This vulnerability falls under the CWE-191 category of Integer Underflow, which occurs when a calculation results in a value that is too small to be represented within the target data type. The affected Snapdragon product lines include automotive systems, compute platforms, connectivity solutions, consumer IoT devices, industrial IoT applications, IoT networks, voice and music processing chips, and wearable technology. The widespread impact across multiple chipset families indicates a fundamental flaw in the packet processing logic that affects various communication protocols and network management functions.
The operational impact of this vulnerability extends beyond simple system instability, potentially enabling attackers to exploit the integer underflow condition to execute arbitrary code or cause denial of service scenarios. When RTCP packets are processed with insufficient validation, the underflow can corrupt memory structures, leading to privilege escalation opportunities or system crashes that disrupt critical communication services. The vulnerability is particularly concerning in automotive applications where real-time communication reliability is paramount for safety systems and vehicle operations.
From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and denial of service attacks, potentially enabling adversaries to gain unauthorized access to system resources or disrupt communication services. The exploitation pathway typically involves sending specifically crafted RTCP packets to the affected device, which then processes these packets through vulnerable code paths. Security professionals should consider implementing network segmentation and packet filtering mechanisms to prevent unauthorized RTCP traffic from reaching vulnerable systems. Additionally, firmware updates from Qualcomm address this issue by implementing proper integer bounds checking and input validation for RTCP packet processing, aligning with industry best practices for secure coding and defensive programming techniques.