CVE-2018-11950 in Snapdragon Mobile
Summary
by MITRE
Unapproved TrustZone applications can be loaded and executed in Snapdragon Mobile in version SD 845, SD 850
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Analysis
by VulDB Data Team • 05/03/2020
The vulnerability identified as CVE-2018-11950 represents a critical security flaw in Qualcomm Snapdragon mobile processors, specifically affecting the SD 845 and SD 850 chipsets. This issue resides within the TrustZone security architecture, which serves as a hardware-based secure processing environment designed to isolate sensitive operations from the main operating system. The flaw allows unauthorized applications to bypass the normal trust verification processes and execute within the secure world, fundamentally undermining the security model that TrustZone was designed to enforce. The vulnerability specifically impacts the loading mechanism of TrustZone applications, creating a pathway for malicious actors to introduce unapproved code into the secure execution environment.
The technical implementation of this vulnerability stems from insufficient validation mechanisms within the TrustZone application loading process. When legitimate TrustZone applications are loaded, the system should verify their authenticity and integrity through cryptographic signatures and access control checks. However, the flaw in Snapdragon SD 845 and SD 850 processors allows attackers to circumvent these verification steps, enabling the execution of unauthorized code within the secure world. This represents a direct violation of the principle of least privilege and trust isolation that forms the foundation of hardware security modules. The vulnerability can be exploited through various attack vectors including malicious firmware updates, specially crafted application packages, or through compromised development environments that could potentially inject malicious code into the secure execution context.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it fundamentally compromises the security architecture of mobile devices. When unauthorized applications can execute within the secure world, attackers gain access to sensitive data processing capabilities, cryptographic key storage, and secure communication channels that were intended to be protected from general execution environments. This vulnerability affects not only individual device security but also enterprise security posture, as it could enable attackers to extract encryption keys, intercept secure communications, or perform man-in-the-middle attacks on sensitive transactions. The implications are particularly severe for mobile devices that handle financial transactions, personal identification data, or corporate confidential information, as the secure world is typically expected to provide protection against such threats. This vulnerability aligns with CWE-284, which addresses improper access control mechanisms, and represents a significant deviation from the expected behavior of secure processing environments.
Mitigation strategies for this vulnerability require a multi-layered approach that addresses both immediate protection and long-term security improvements. Device manufacturers should implement firmware updates that correct the TrustZone application loading validation mechanisms, ensuring that only properly signed and approved applications can execute within the secure world. System-level protections should include enhanced code integrity checks, improved cryptographic verification processes, and regular security audits of the TrustZone environment. Security researchers and device manufacturers should also consider implementing runtime monitoring systems that can detect anomalous behavior patterns indicative of unauthorized secure world execution. The vulnerability demonstrates the importance of maintaining robust hardware security boundaries and highlights the need for continuous security assessment of trusted execution environments. Organizations should also review their mobile security policies to ensure that devices running vulnerable firmware are properly managed and updated according to security best practices. This vulnerability serves as a reminder of the critical importance of hardware-level security mechanisms and the potential consequences when these protections are compromised.