CVE-2021-0588 in Android
Summary
by MITRE • 07/15/2021
In processInboundMessage of MceStateMachine.java, there is a possible SMS disclosure due to a missing permission check. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.1 Android-9Android ID: A-177238342
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Analysis
by VulDB Data Team • 07/18/2021
The vulnerability identified as CVE-2021-0588 resides within the Android messaging framework, specifically in the MceStateMachine.java component that handles inbound SMS message processing. This flaw represents a critical permission oversight that allows unauthorized access to sensitive SMS data through a missing validation check during message handling operations. The vulnerability affects Android versions 8.1 and 9, encompassing a significant portion of devices that rely on the Android messaging infrastructure for communication management.
The technical root cause stems from insufficient authorization verification within the processInboundMessage method of the MceStateMachine class, which operates as part of the mobile communication engine responsible for managing SMS transmission and reception. When processing incoming messages, the system fails to validate whether the requesting process possesses the necessary permissions to access or disclose SMS content, creating a pathway for unauthorized information disclosure. This missing permission check occurs at a critical processing stage where the system should validate access rights before allowing data manipulation or retrieval operations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables local privilege escalation without requiring additional execution privileges or user interaction. Attackers can exploit this weakness to access SMS messages stored on the device, potentially obtaining sensitive personal information, authentication codes, financial data, or confidential communications without any elevated privileges. The vulnerability's accessibility means that any application with basic system access could leverage this flaw to extract SMS data, making it particularly concerning for devices with compromised applications or malicious software.
This vulnerability maps directly to CWE-284, which addresses improper access control issues in software systems, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter usage. The lack of proper permission validation creates an access control weakness that allows unauthorized processes to bypass normal security boundaries. Security professionals should note that this vulnerability demonstrates the importance of implementing comprehensive access control mechanisms at all levels of system processing, particularly within communication frameworks where sensitive data flows continuously.
Mitigation strategies should focus on implementing robust permission validation checks within the messaging framework, ensuring that all message processing operations verify appropriate access rights before executing data operations. Android security updates should enforce strict permission boundaries for SMS handling components, and developers should implement additional validation layers in messaging system components to prevent unauthorized access to sensitive communication data. Organizations should also consider monitoring for suspicious messaging framework access patterns and implement regular security assessments to identify similar permission gaps in other system components.