CVE-2020-3634 in Snapdragon Auto
Summary
by MITRE
u'Multiple Read overflows issue due to improper length check while decoding Generic NAS transport/EMM info' in Snapdragon Auto, Snapdragon Compute, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Wearables in APQ8053, APQ8096AU, APQ8098, Kamorta, MDM9150, MDM9205, MDM9206, MDM9607, MDM9625, MDM9635M, MDM9640, MDM9645, MDM9650, MDM9655, MSM8905, MSM8909W, MSM8917, MSM8953, MSM8996AU, MSM8998, Nicobar, QCM2150, QCS605, QCS610, QM215, Rennell, SA415M, Saipan, SC7180, SDA660, SDA845, SDM429, SDM429W, SDM439, SDM450, SDM630, SDM632, SDM636, SDM660, SDM670, SDM710, SDM845, SDM850, SDX20, SDX24, SDX55, SM6150, SM7150, SM8150, SXR1130
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Analysis
by VulDB Data Team • 09/09/2020
This vulnerability represents a critical memory safety issue affecting multiple Qualcomm Snapdragon chipsets across various product lines including automotive, mobile, and IoT devices. The flaw manifests as multiple read overflows occurring during the decoding process of Generic NAS transport/EMM information, which is a fundamental component of 3G and 4G cellular communication protocols. The vulnerability stems from inadequate length validation mechanisms within the cellular stack implementation, specifically in how the system processes incoming network messages that contain mobility management information elements. These read overflows occur when the system attempts to read data beyond the allocated buffer boundaries without proper bounds checking, creating potential exploitation vectors for malicious actors to access sensitive memory regions.
The technical exploitation of this vulnerability requires understanding the cellular protocol stack architecture and how Generic NAS transport messages are processed within the modem firmware. When a device receives a specially crafted network message containing malformed EMM information elements, the decoding routine fails to validate the actual message length against the expected buffer size. This improper length check allows attackers to manipulate the parsing logic to read beyond allocated memory segments, potentially exposing sensitive data or enabling arbitrary code execution. The vulnerability affects a wide range of Snapdragon chipsets spanning multiple generations from older models like MSM8905 to newer flagship processors such as SDM850 and SDX55, indicating a systemic issue within Qualcomm's cellular protocol implementation across their product portfolio. The impact extends beyond simple data corruption as these overflows can lead to complete system compromise and unauthorized access to cellular communication capabilities.
The operational implications of this vulnerability are severe given the widespread deployment of affected Snapdragon chipsets in mobile devices, automotive systems, and IoT products. Attackers could potentially exploit this weakness to intercept cellular communications, gain unauthorized access to device functionality, or execute malicious code on affected systems. The vulnerability's presence in automotive platforms like Snapdragon Auto suggests potential risks to vehicle safety systems and connected car services, while its presence in IoT devices indicates broader concerns about industrial control systems and smart infrastructure. The attack surface is particularly concerning because these chipsets power billions of devices globally, making the potential impact of exploitation extremely broad. Organizations using affected devices may experience data breaches, unauthorized surveillance, or complete system compromise without proper mitigation measures. The vulnerability's classification aligns with CWE-129, which addresses improper validation of length of inputs to buffers, and can be mapped to ATT&CK technique T1059 for command and control through cellular networks.
Mitigation strategies for this vulnerability require a multi-layered approach addressing both software and hardware components. Immediate firmware updates from device manufacturers are essential to patch the buffer overflow conditions in the cellular protocol stack. System administrators should implement network monitoring to detect anomalous cellular traffic patterns that might indicate exploitation attempts. Device-level protections include enabling memory protection features such as stack canaries and address space layout randomization to make exploitation more difficult. Organizations should also consider network segmentation to limit the potential impact of cellular-based attacks and implement robust incident response procedures for detecting and responding to exploitation attempts. The vulnerability highlights the importance of proper input validation and bounds checking in embedded systems, particularly those handling network communications where malformed data could lead to system compromise. Given the widespread nature of affected chipsets, manufacturers must ensure comprehensive testing of firmware updates to prevent regressions while maintaining device functionality. Regular security assessments of cellular protocol implementations should become standard practice to identify and remediate similar vulnerabilities before they can be exploited in the field.