CVE-2020-9531 in MIUI
Summary
by MITRE
An issue was discovered on Xiaomi MIUI V11.0.5.0.QFAEUXM devices. In the Web resources of GetApps(com.xiaomi.mipicks), the parameters passed in are read and executed. After reading the resource files, relevant components open the link of the incoming URL. Although the URL is safe and can pass security detection, the data carried in the parameters are loaded and executed. An attacker can use NFC tools to get close enough to a user's unlocked phone to cause apps to be installed and information to be leaked. This is fixed on version: 2001122.
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Analysis
by VulDB Data Team • 04/10/2024
The vulnerability identified as CVE-2020-9531 represents a critical security flaw in Xiaomi MIUI version 11.0.5.0.QFAEUXM affecting the GetApps application component. This issue manifests through improper parameter handling within the web resource processing mechanism of the application, creating a dangerous execution flow that can be exploited by remote attackers. The vulnerability stems from the application's failure to properly sanitize and validate input parameters passed through URL schemes, allowing malicious data to be interpreted and executed within the context of the running application. The flaw specifically affects the GetApps component which is responsible for handling external web resources and app installations through the Miui platform.
The technical implementation of this vulnerability involves a dangerous combination of parameter injection and automatic URL processing within the GetApps application framework. When the application processes incoming URLs containing parameters, it fails to properly validate or sanitize these inputs before executing them within the application context. This creates a path for remote code execution through crafted parameter values that can trigger unauthorized app installations or data exfiltration. The vulnerability is particularly concerning because it operates through NFC proximity attacks, eliminating the need for traditional network-based exploitation methods. The attack vector leverages the fact that when a user's phone is unlocked, NFC communication can be initiated from nearby devices, allowing attackers to inject malicious parameters directly into the GetApps processing pipeline.
The operational impact of this vulnerability extends beyond simple unauthorized installations to encompass complete system compromise through information leakage and persistent malicious presence. Attackers can exploit this weakness to install arbitrary applications without user consent, potentially deploying malware or spyware that can monitor user activities, extract personal data, or establish persistent backdoors. The NFC-based attack method is particularly dangerous because it requires minimal physical proximity and can be executed without user awareness, making it an ideal vector for targeted attacks against specific individuals or groups. The vulnerability affects the core MIUI security model by bypassing normal application sandboxing and permission checking mechanisms that should prevent unauthorized installations. This represents a fundamental failure in the application's input validation and execution control mechanisms, creating a persistent threat vector that can be exploited repeatedly.
The security implications of CVE-2020-9531 align with CWE-74 and CWE-79 standards, which address injection flaws and cross-site scripting vulnerabilities respectively. The vulnerability demonstrates characteristics of CWE-94, representing unrestricted execution of code through parameter manipulation, and CWE-20, addressing input validation failures that lead to security breaches. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for command and scripting interpreter and T1190 for exploitation of remote services, while also supporting T1068 for local privilege escalation through unauthorized application installation. The fix implemented by Xiaomi in version 2001122 addresses these concerns through enhanced parameter validation and input sanitization mechanisms. The mitigation strategy involves proper URL parsing with strict validation of parameter contents, implementation of secure coding practices for web resource handling, and strengthening NFC security controls to prevent unauthorized communication initiation. Organizations should implement comprehensive security monitoring for similar vulnerabilities in third-party applications and ensure timely patch deployment to protect against both current and emerging threats. The vulnerability underscores the importance of secure parameter handling in mobile application development and highlights the need for robust input validation mechanisms in all components that process external data sources.