CVE-2019-20544 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with O(8.x) and P(9.0) (Exynos chipsets) software. There is an out-of-bounds write in the ICCC Trustlet. The Samsung ID is SVE-2019-15274 (November 2019).
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Analysis
by VulDB Data Team • 10/04/2020
The vulnerability CVE-2019-20544 represents a critical out-of-bounds write flaw within the ICCC Trustlet component of Samsung's mobile device firmware, specifically affecting devices running on Exynos chipsets with operating system versions Oreo 8.x and Pie 9.0. This issue resides within the trusted execution environment of the device, making it particularly concerning from a security perspective. The ICCC Trustlet operates as a security-sensitive component responsible for handling cryptographic operations and secure communications, and the vulnerability manifests as an improper bounds checking mechanism that allows arbitrary memory writes beyond allocated buffer boundaries. The Samsung internal identification SVE-2019-15274 indicates this was recognized and addressed by the vendor as part of their security advisory process, highlighting the severity of the flaw.
This out-of-bounds write vulnerability falls under the CWE-787 category of "Out-of-bounds Write" which represents a fundamental memory safety issue where an application writes data past the end of a buffer, potentially corrupting adjacent memory regions. The flaw specifically impacts the ICCC Trustlet which operates in a privileged security context, making this vulnerability particularly dangerous as it could enable attackers to manipulate critical system components or execute arbitrary code within the secure execution environment. The Exynos chipset architecture adds complexity to the attack surface since it involves multiple security domains including the application processor, secure world, and hardware security modules that must maintain strict isolation boundaries.
The operational impact of this vulnerability extends beyond simple memory corruption, as it represents a potential path for privilege escalation attacks within the device's security architecture. Attackers could leverage this flaw to gain unauthorized access to sensitive cryptographic keys, manipulate secure communication channels, or potentially compromise the integrity of the device's trusted execution environment. The vulnerability affects the fundamental security infrastructure of Samsung's mobile devices, potentially undermining the security model that relies on isolated secure processing environments for handling sensitive operations. This flaw could enable adversaries to bypass security controls designed to protect against malicious software and unauthorized access to device resources.
Mitigation strategies for CVE-2019-20544 should prioritize the immediate application of Samsung's security patches and firmware updates released in response to this vulnerability. Organizations and individuals should ensure their Samsung devices are updated to the latest software versions that contain fixes for the ICCC Trustlet implementation. The vulnerability's nature as a memory safety issue suggests that defensive programming techniques such as bounds checking, stack canaries, and memory protection mechanisms should be implemented at the application level. Additionally, security monitoring should be enhanced to detect anomalous behavior in secure execution environments, and device manufacturers should consider implementing runtime integrity checks to prevent exploitation of similar vulnerabilities in the future. This vulnerability underscores the importance of maintaining up-to-date security implementations in mobile device ecosystems and highlights the critical need for robust security testing of trusted execution environments.