CVE-2018-3595 in Snapdragon Automobile
Summary
by MITRE
Anti-rollback can be bypassed in replay scenario during app loading due to improper error handling of RPMB writes in snapdragon automobile, snapdragon mobile and snapdragon wear in versions MDM9206, MDM9607, MDM9650, MSM8996AU, SD 210/SD 212/SD 205, SD 425, SD 430, SD 450, SD 625, SD 650/52, SD 712 / SD 710 / SD 670, SD 820, SD 820A, SD 835, SD 845 / SD 850, SDA660, SDX24, SXR1130
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Analysis
by VulDB Data Team • 05/03/2020
The vulnerability described in CVE-2018-3595 represents a critical weakness in the anti-rollback protection mechanisms of Qualcomm Snapdragon automotive and mobile platforms. This issue specifically affects devices that utilize RPMB (Replay Protection Memory Block) for secure storage of critical boot and application data. The flaw manifests during application loading scenarios where the system fails to properly handle errors encountered during RPMB write operations, effectively allowing attackers to bypass intended security measures that prevent older firmware versions from being loaded onto devices. The vulnerability impacts a wide range of Snapdragon chipsets including the MDM9206, MDM9607, MDM9650, MSM8996AU, and numerous SD series processors spanning from entry-level to high-end mobile and automotive platforms.
The technical root cause of this vulnerability lies in the improper error handling within the RPMB write operation sequence during application loading processes. When RPMB writes fail or encounter issues during the boot or application loading sequence, the system should ideally abort the operation and prevent the loading of potentially compromised software. However, the flawed implementation allows the system to continue processing even when RPMB write operations fail, effectively rendering the anti-rollback protection mechanism ineffective. This error handling failure creates a replay scenario where malicious actors can exploit the system's inability to properly validate or reject invalid firmware updates, potentially enabling downgrade attacks or the installation of unauthorized software versions. The vulnerability operates at the hardware-software interface level, leveraging the fundamental security assumptions about RPMB integrity and write validation.
The operational impact of this vulnerability extends significantly across both automotive and mobile device ecosystems, particularly affecting vehicles equipped with Snapdragon automotive platforms and smartphones utilizing the affected mobile chipsets. Attackers could potentially exploit this weakness to downgrade firmware to older versions containing known vulnerabilities, bypass security patches, or install malicious code that would normally be prevented by the anti-rollback mechanisms. In automotive contexts, this could enable attackers to compromise vehicle security systems, potentially affecting critical functions such as engine control, braking systems, or infotainment systems. The vulnerability is particularly concerning because it affects multiple generations of Snapdragon processors, creating a widespread attack surface that spans from budget smartphones to high-end automotive systems. The risk is compounded by the fact that the vulnerability operates silently during normal operation, making detection and prevention challenging for end users and system administrators.
Mitigation strategies for CVE-2018-3595 should focus on both immediate firmware updates and architectural improvements to error handling mechanisms. Qualcomm has released security patches addressing this vulnerability, and device manufacturers should prioritize deploying these updates across affected platforms. System administrators and security professionals should implement enhanced monitoring of RPMB write operations and establish more robust error handling procedures that prevent system continuation when critical write operations fail. The vulnerability aligns with CWE-248, which addresses improper exception handling, and relates to ATT&CK technique T1059 for execution through boot processes. Organizations should also consider implementing additional security controls such as hardware-based root of trust verification, enhanced firmware integrity checks, and regular security assessments of embedded systems to prevent similar issues in other components of their security infrastructure.