CVE-2017-18124 in Snapdragon Automobile
Summary
by MITRE
During secure boot, addition is performed on uint8 ptrs which led to overflow issue in Small Cell SoC, Snapdragon Automobile, Snapdragon Mobile, Snapdragon Wear in version FSM9055, IPQ4019, MDM9206, MDM9607, 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 617, SD 625, SD 650/52, SD 800, SD 810, SD 820, SD 820A, SD 835, SD 845, SD 850, SDA660, SDX20
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Analysis
by VulDB Data Team • 05/03/2020
This vulnerability represents a critical integer overflow condition that occurs during the secure boot process of Qualcomm Snapdragon-based devices, affecting a wide range of mobile and automotive SoC platforms. The flaw manifests when addition operations are performed on uint8 pointer values, creating conditions where arithmetic overflow can lead to unpredictable behavior in the boot sequence. The vulnerability impacts devices running version FSM9055, IPQ4019, and multiple MDM and MSM series processors, including the widely deployed SD 210, SD 410, SD 615, SD 800, and SD 845 platforms. The root cause lies in improper handling of unsigned 8-bit integer arithmetic during secure boot operations, where the addition of pointer values exceeds the maximum representable value for uint8 data type, typically 255.
The technical implications of this vulnerability extend beyond simple arithmetic overflow, as it directly affects the integrity of the secure boot chain that is fundamental to device security. During the boot process, the system relies on proper validation of firmware components to ensure only authenticated code executes, but this protection mechanism becomes compromised when integer overflow occurs. The overflow can potentially lead to memory corruption, allowing attackers to manipulate boot loaders or firmware components, thereby undermining the entire security framework. This vulnerability aligns with CWE-191, which specifically addresses integer underflow and overflow conditions, and represents a significant concern for automotive and mobile device security. The ATT&CK framework categorizes this as a boot integrity attack, potentially enabling adversaries to bypass secure boot protections through manipulation of arithmetic operations during system initialization.
The operational impact of this vulnerability is severe across the affected platforms, as it can enable attackers to execute arbitrary code during the boot process, potentially leading to full system compromise. Mobile devices utilizing these processors, including smartphones, tablets, and automotive infotainment systems, become vulnerable to attacks that can undermine device security and potentially allow for persistent backdoor access. The widespread deployment of these SoC platforms across multiple device categories means that the vulnerability affects not only consumer electronics but also critical automotive systems where secure boot integrity is paramount. Attackers could exploit this condition to load malicious firmware or modify boot loaders, potentially gaining root access to the device before normal security mechanisms are operational. The vulnerability's presence in both mobile and automotive platforms, including the SDX20 and FSM9055 variants, indicates the scope of potential impact across different market segments.
Mitigation strategies for this vulnerability require immediate firmware updates from device manufacturers, as the flaw exists within the core boot process that cannot be patched through standard software updates. System administrators and device manufacturers must prioritize deployment of patched firmware versions that address the integer overflow condition in the secure boot implementation. The recommended approach involves implementing proper bounds checking and overflow detection mechanisms in the boot loader code, particularly around pointer arithmetic operations. Additionally, runtime protections such as stack canaries, address space layout randomization, and enhanced memory protection mechanisms should be considered to prevent exploitation of similar vulnerabilities. Given the nature of the vulnerability, the security community should implement monitoring for anomalous boot behavior and memory access patterns that could indicate exploitation attempts. Organizations using affected platforms should conduct thorough security assessments of their device fleet and consider implementing additional security controls to compensate for the vulnerability until complete firmware patches are deployed. The vulnerability demonstrates the critical importance of proper integer handling in security-critical code paths and underscores the need for comprehensive security testing of boot processes in embedded systems.