CVE-2017-18302 in Snapdragon Automobile
Summary
by MITRE
In Snapdragon (Automobile ,Mobile) in version MSM8996AU, SD 425, SD 427, SD 430, SD 435, SD 450, SD 625, SD 650/52, SD 820, SD 820A, SD 835, SDA660, SDM429, SDM439, SDM630, SDM632, SDM636, SDM660, Snapdragon_High_Med_2016, a crafted HLOS client can modify the structure in memory passed to a QSEE application between the time of check and the time of use, resulting in arbitrary writes to TZ kernel memory regions.
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Analysis
by VulDB Data Team • 05/17/2023
This vulnerability exists within Qualcomm's Snapdragon automotive and mobile platform ecosystems affecting multiple chipsets including MSM8996AU, SD 425 through SDM660 variants. The flaw represents a classic time-of-check to time-of-use race condition that allows malicious HLOS clients to manipulate memory structures before they are processed by the TrustZone kernel application. The vulnerability stems from insufficient validation mechanisms that permit unauthorized modification of memory structures between the moment when access controls are verified and when the actual memory operations occur. This architectural weakness enables attackers to gain elevated privileges and execute arbitrary code within the secure kernel environment.
The technical exploitation of CVE-2017-18302 leverages the inherent timing gap in Qualcomm's security model where memory validation occurs before the actual execution phase. When a malicious HLOS client crafts a specific payload, it can manipulate data structures that are subsequently passed to QSEE applications without proper re-validation. This creates an opportunity for attackers to overwrite critical kernel memory regions with malicious content, effectively bypassing the security boundaries that separate trusted and untrusted execution environments. The vulnerability specifically targets the TrustZone execution environment which is designed to protect sensitive operations and data from unauthorized access.
From an operational perspective, this vulnerability poses significant risks to automotive and mobile device security as it allows attackers to escalate privileges from user mode to kernel mode within the secure execution environment. The impact extends beyond individual device compromise to potentially affect vehicle safety systems in automotive applications where Snapdragon platforms are integrated. Attackers could exploit this vulnerability to modify critical system functions, access encrypted data, or disable security features. The widespread adoption of affected chipsets across multiple device categories amplifies the potential attack surface and the number of vulnerable systems.
The vulnerability aligns with CWE-367 Time-of-Check to Time-of-Use (TOCTOU) weakness category which is commonly exploited in privilege escalation scenarios. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including privilege escalation through kernel exploits and persistence mechanisms within secure execution environments. The attack requires a crafted HLOS client which suggests that exploitation would typically occur through compromised applications or malicious firmware updates. Organizations should implement comprehensive patch management strategies targeting affected Snapdragon chipsets and consider monitoring for anomalous behavior in secure execution environments. Additionally, runtime protection mechanisms and memory integrity checks should be deployed to detect and prevent exploitation attempts.