CVE-2018-13896 in Snapdragon Auto
Summary
by MITRE
XBL_SEC image authentication and other crypto related validations are accessible to a compromised OEM XBL Loader due to missing lock at XBL_SEC stage.. in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer Electronics Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wired Infrastructure and Networking in MDM9206, MDM9607, MDM9650, MDM9655, MSM8996AU, QCS404, QCS605, Qualcomm 215, SD 410/12, SD 425, SD 427, SD 430, SD 435, SD 439 / SD 429, SD 450, SD 625, SD 632, SD 636, SD 712 / SD 710 / SD 670, SD 820, SD 820A, SD 835, SD 845 / SD 850, SD 855, SD 8CX, SDA660, SDM439, SDM630, SDM660, Snapdragon_High_Med_2016, SXR1130
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Analysis
by VulDB Data Team • 07/09/2020
The vulnerability described in CVE-2018-13896 represents a critical security flaw in Qualcomm's bootloader implementation affecting multiple Snapdragon chipsets across various product categories. This issue stems from insufficient protection mechanisms during the XBL_SEC stage of the boot process, where cryptographic validations and image authentication checks should remain secure but are instead accessible to a compromised OEM XBL Loader. The fundamental problem lies in the absence of proper locking mechanisms that would normally prevent unauthorized access to critical security functions during the early boot phases.
The technical flaw manifests as a missing lock mechanism at the XBL_SEC stage, which allows a malicious actor who has already compromised the OEM XBL Loader to bypass cryptographic validation processes. This creates a pathway for attackers to manipulate or replace critical boot components without proper authentication, effectively undermining the entire chain of trust that should protect the device's firmware integrity. The vulnerability affects a broad range of Qualcomm chipsets including the MDM9206, MDM9607, MDM9650, MDM9655, MSM8996AU, QCS404, QCS605, and numerous others spanning mobile, automotive, IoT, and networking applications. This widespread impact across different chipset families demonstrates the systemic nature of the security weakness.
The operational impact of this vulnerability is severe as it enables attackers to perform unauthorized firmware modifications, potentially leading to complete device compromise. An attacker who gains access to the XBL stage can bypass all cryptographic protections, allowing for the installation of malicious bootloaders or firmware components that can persist across device reboots. This creates a persistent backdoor that can be used for various malicious activities including data exfiltration, system monitoring, or further exploitation of other system components. The vulnerability directly relates to CWE-284 which describes improper access control, and maps to ATT&CK technique T1068 which covers exploit for privilege escalation.
The security implications extend beyond simple unauthorized access as this flaw can enable attackers to circumvent hardware-based security features designed to protect against firmware tampering. The compromised bootloader can potentially allow for the execution of malicious code before the operating system loads, providing attackers with root-level access to the device. This vulnerability is particularly dangerous in automotive applications where the compromised vehicle systems could be manipulated, or in IoT devices where persistent access could enable large-scale attacks. Organizations should implement immediate mitigations including firmware updates from device manufacturers, hardware-level security monitoring, and enhanced network segmentation to prevent lateral movement of attackers who might exploit this vulnerability. The absence of proper locking mechanisms during the critical XBL_SEC authentication stage creates a fundamental weakness in the device's security architecture that requires urgent attention and remediation across all affected platforms.