CVE-2019-20590 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with O(8.x) (Qualcomm chipsets) software. There is an integer underflow in the Secure Storage Trustlet. The Samsung ID is SVE-2019-13952 (July 2019).
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Analysis
by VulDB Data Team • 10/04/2020
The vulnerability identified as CVE-2019-20590 represents a critical integer underflow condition within the Secure Storage Trustlet component of Samsung mobile devices running Android 8.x operating system versions on Qualcomm chipsets. This flaw exists within the secure element implementation that governs cryptographic operations and secure storage management on these devices. The Secure Storage Trustlet serves as a critical security module responsible for protecting sensitive data through cryptographic operations and maintaining the integrity of secure storage mechanisms. The integer underflow occurs when the system processes certain input values that cause arithmetic operations to wrap around to negative values, potentially leading to unexpected behavior in memory management and access control mechanisms. This vulnerability specifically affects Samsung devices manufactured with Qualcomm Snapdragon chipsets and operating on Android 8.x versions, making it particularly concerning given the widespread adoption of these hardware and software combinations across the mobile ecosystem.
The technical exploitation of this integer underflow vulnerability creates a pathway for attackers to potentially bypass security controls within the secure storage framework. When the trustlet processes malformed input data that triggers the underflow condition, it can result in incorrect memory pointer calculations or buffer boundary checks that may allow unauthorized access to protected data. The underlying nature of the vulnerability stems from inadequate input validation and boundary checking within the cryptographic processing routines. According to CWE classification, this represents a CWE-191 Integer Underflow (Wrap or Wraparound) which is categorized under the broader weakness of improper integer handling in security-critical contexts. The vulnerability's impact is amplified by the fact that it operates within the secure storage trustlet, which typically runs with elevated privileges and has direct access to sensitive cryptographic keys and protected data stores. This creates a potential attack surface where malicious actors could manipulate the trustlet's behavior to extract or modify protected information.
The operational impact of CVE-2019-20590 extends beyond simple data exposure to encompass potential compromise of the entire device security architecture. Attackers who successfully exploit this vulnerability could gain unauthorized access to cryptographic keys stored in secure storage, potentially enabling them to decrypt sensitive user data, forge digital signatures, or impersonate legitimate device components. The vulnerability affects devices that rely on Qualcomm chipsets for their secure element functionality, which includes critical security features such as hardware-based encryption, secure boot processes, and trusted execution environments. This compromise could lead to credential theft, unauthorized financial transactions, or complete device takeover depending on the specific implementation details of the affected Samsung devices. The vulnerability's discovery and subsequent patching through Samsung's security updates demonstrate the critical nature of such flaws in mobile security ecosystems where the secure storage mechanisms form the foundation of device-level protection.
Mitigation strategies for CVE-2019-20590 primarily focus on applying official security patches provided by Samsung and Qualcomm, which typically involve firmware updates that correct the integer underflow condition within the Secure Storage Trustlet. Organizations and users should prioritize immediate deployment of these patches to prevent exploitation, particularly in environments where mobile devices handle sensitive corporate or personal information. System administrators should implement comprehensive vulnerability management programs that include regular monitoring of security advisories from both Samsung and Qualcomm, as well as maintaining up-to-date device firmware across all managed endpoints. The vulnerability's characteristics align with ATT&CK technique T1552.001 (Credentials in Files) and T1059.001 (Command and Scripting Interpreter), suggesting that exploitation could involve credential extraction or command execution within the secure environment. Additionally, network administrators should consider implementing device profiling and monitoring solutions that can detect anomalous behavior patterns consistent with exploitation attempts, particularly in environments where these vulnerable devices may be connected to corporate networks. The remediation process should also include comprehensive security assessments to verify that the patch has been correctly applied and that no residual vulnerabilities exist in related components of the secure storage framework.