CVE-2018-5916 in Snapdragon Automobile
Summary
by MITRE
Buffer overread while decoding PDP modify request or network initiated secondary PDP activation in Snapdragon Automobile, Snapdragon Mobile and Snapdragon Wear in versions MDM9206, MDM9607, MDM9615, MDM9625, MDM9635M, MDM9640, MDM9645, MDM9650, MDM9655, MSM8909W, MSM8996AU, SD 210/SD 212/SD 205, SD 410/12, SD 425, SD 430, SD 450, SD 615/16/SD 415, SD 625, SD 650/52, SD 810, SD 820, SD 820A, SD 835, SD 845, SD 850, SDA660, SDA845, SDX20, SXR1130.
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Analysis
by VulDB Data Team • 05/04/2020
This vulnerability represents a critical buffer overread condition in the cellular modem processing stack of Qualcomm Snapdragon chipsets affecting automotive, mobile, and wearable devices. The flaw occurs during the handling of PDP (Packet Data Protocol) modify requests or network-initiated secondary PDP activation procedures, which are fundamental components of 3G and 4G cellular data session management. The vulnerability stems from inadequate bounds checking when decoding incoming network messages, specifically in the way the modem processes protocol control information fields that define packet data sessions. This buffer overread condition allows an attacker to potentially read data from adjacent memory locations beyond the intended buffer boundaries, which could expose sensitive information including cryptographic keys, session tokens, or other confidential data stored in the device's memory.
The technical implementation of this vulnerability involves the modem's packet processing engine receiving malformed or specially crafted PDP modify requests from the cellular network. When the modem attempts to decode these requests, it fails to properly validate the length of incoming data fields, leading to an overread condition where the processor reads beyond allocated memory boundaries. This condition can be triggered through legitimate network communication channels, making it particularly dangerous as it requires no physical access or special privileges to exploit. The affected Snapdragon chipsets span multiple generations and product lines including the MDM9206, MDM9607, and various MSM8996AU variants, indicating a widespread impact across Qualcomm's automotive and mobile platform portfolio. The vulnerability is categorized under CWE-125 as an out-of-bounds read, which aligns with the ATT&CK framework's T1059.007 technique for command and scripting interpreter, as exploitation could enable further attack vectors through information disclosure.
The operational impact of this vulnerability extends beyond simple information disclosure, as the read data could contain sensitive session information that could be leveraged for more sophisticated attacks. An attacker positioned within the network could potentially use this vulnerability to reconstruct session state information, potentially enabling session hijacking or man-in-the-middle attacks on cellular communications. The vulnerability affects devices that rely on cellular connectivity for critical functions including vehicle telematics, mobile payment systems, and wearable health monitoring devices. Given that these chipsets are deployed in automotive applications, the potential for exploitation could lead to unauthorized access to vehicle systems or data exfiltration from connected vehicles. The attack surface is particularly concerning as it can be triggered through legitimate network traffic, making it difficult to detect and prevent through conventional network monitoring techniques.
Mitigation strategies for this vulnerability should focus on firmware updates from device manufacturers, as Qualcomm has released patches addressing the buffer overread condition. Network operators should also implement monitoring for suspicious PDP modify request patterns that could indicate exploitation attempts. Device manufacturers should consider implementing additional runtime protections such as stack canaries or memory sanitization techniques to detect and prevent exploitation attempts. The vulnerability highlights the importance of proper input validation in embedded systems and underscores the need for comprehensive security testing of modem firmware components. Organizations should also implement network segmentation and monitoring to detect anomalous cellular traffic patterns that could indicate exploitation attempts. Given the widespread deployment of affected chipsets, coordinated patch management across automotive, mobile, and wearable device ecosystems is essential to prevent exploitation. The vulnerability serves as a reminder of the critical security considerations for embedded cellular modems and the potential for remote code execution through seemingly benign network protocol processing flaws.