CVE-2021-25388 in Smart Phone
Summary
by MITRE • 06/11/2021
Improper caller check vulnerability in Knox Core prior to SMR MAY-2021 Release 1 allows attackers to install arbitrary app.
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Analysis
by VulDB Data Team • 06/14/2021
The vulnerability identified as CVE-2021-25388 represents a critical improper caller check flaw within the Knox Core component of Samsung's Android-based mobile platform. This weakness exists in Knox Core versions prior to the SMR MAY-2021 Release 1 security patch, creating a significant attack surface that adversaries can exploit to gain unauthorized application installation privileges. The vulnerability stems from insufficient validation of caller identity and permissions within the core security framework that protects enterprise mobile devices. This flaw specifically impacts Samsung Knox-enabled devices that utilize the Samsung Knox platform for enterprise security management and device protection.
The technical implementation of this vulnerability resides in the caller verification mechanisms within the Knox Core service architecture. When applications attempt to perform privileged operations related to application installation, the system fails to properly validate whether the calling process possesses the necessary authorization levels. This improper caller check allows malicious actors to forge or manipulate the caller identity, effectively bypassing the intended security controls that should restrict application installation to authorized administrators or legitimate system processes. The vulnerability operates at the kernel or system service level where Knox Core manages device security policies, making it particularly dangerous as it can be exploited without requiring user interaction or elevated privileges beyond what the system typically grants to standard applications.
The operational impact of this vulnerability extends beyond simple unauthorized application installation, as it fundamentally compromises the integrity of the enterprise mobile security model. Attackers who successfully exploit this flaw can install malicious applications that operate with elevated privileges, potentially leading to full device compromise, data exfiltration, or further lateral movement within corporate networks. This vulnerability particularly affects organizations that rely on Samsung Knox for mobile device management and enterprise security, as it undermines the core security assumptions that protect corporate data and prevent unauthorized access to sensitive information. The exploitability of this vulnerability means that even a basic malicious application could potentially escalate privileges and gain control over the entire device security framework.
Organizations should implement immediate mitigations including deploying the SMR MAY-2021 Release 1 security patches that address this specific caller check vulnerability. System administrators must also conduct comprehensive vulnerability assessments to identify any devices running affected Knox Core versions and ensure all enterprise mobile devices receive timely security updates. Additional defensive measures include implementing strict mobile device management policies, monitoring for unauthorized application installations, and maintaining network segmentation to limit the potential impact of successful exploitation. From a cybersecurity framework perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and represents a significant weakness in the principle of least privilege implementation within the Knox security architecture. The attack surface this vulnerability creates can be mapped to ATT&CK technique T1195.001 (Supply Chain Compromise) and T1059.003 (Command and Scripting Interpreter) when exploited for persistent access and malicious code execution. Organizations should also consider implementing behavioral monitoring solutions that can detect anomalous application installation patterns that might indicate exploitation attempts.