CVE-2019-20589 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with O(8.x) and P(9.0) (with TEEGRIS) software. There is type confusion in the SKPM Trustlet, leading to arbitrary code execution. The Samsung ID is SVE-2019-14892 (August 2019).
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Analysis
by VulDB Data Team • 10/04/2020
The vulnerability identified as CVE-2019-20589 represents a critical type confusion flaw within the SKPM Trustlet component of Samsung's mobile operating systems. This issue affects devices running Android 8.x and 9.0 versions that utilize the TEEGRIS security framework, creating a significant attack surface that could be exploited by malicious actors. The vulnerability resides in the secure kernel implementation where improper type validation allows attackers to manipulate memory structures and execute arbitrary code with elevated privileges. The Samsung ID SVE-2019-14892 was assigned to track this specific weakness, indicating its classification as a serious security concern requiring immediate attention.
The technical root cause of this vulnerability stems from inadequate type checking mechanisms within the SKPM Trustlet implementation. Type confusion occurs when a program incorrectly handles data types during runtime operations, allowing an attacker to manipulate memory layout and execute unintended code sequences. This particular flaw enables attackers to leverage the trustlet's privileged execution environment to bypass normal security boundaries and gain unauthorized access to sensitive system resources. The vulnerability's classification aligns with CWE-466, which specifically addresses the issue of returning a pointer to a data structure that is not of the expected type, leading to unpredictable behavior and potential code execution.
The operational impact of CVE-2019-20589 extends beyond simple privilege escalation, as it provides attackers with access to the Trusted Execution Environment's secure processing capabilities. This vulnerability could enable adversaries to extract sensitive cryptographic keys, manipulate secure storage mechanisms, or gain persistent access to device functionalities that should remain protected from regular user applications. The TEEGRIS framework's design intent was to provide a secure environment for sensitive operations, but this type confusion flaw undermines that security model entirely. Attackers could potentially exploit this vulnerability to perform man-in-the-middle attacks on secure communications, compromise device integrity, or establish persistent backdoors that survive device reboots.
Mitigation strategies for this vulnerability require immediate deployment of Samsung's security patches and firmware updates that address the specific type confusion issue within the SKPM Trustlet. System administrators should prioritize updating all affected Samsung devices running Android 8.x and 9.0 versions to ensure proper type validation mechanisms are in place. Organizations implementing mobile device management solutions should verify that all enrolled devices have received the necessary security updates and monitor for any suspicious activity that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1059.007, which covers command and scripting interpreter usage, as exploitation could involve executing malicious code within the compromised secure environment. Additionally, security professionals should consider implementing network monitoring solutions to detect potential exploitation attempts targeting this specific vulnerability, as the attack surface includes both local and remote exploitation capabilities.