CVE-2021-0486 in Android
Summary
by MITRE • 07/15/2021
In onPackageAddedInternal of PermissionManagerService.java, there is possible access to external storage due to a permissions bypass. This could lead to local escalation of privilege with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11Android ID: A-171430330
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Analysis
by VulDB Data Team • 07/18/2021
The vulnerability identified as CVE-2021-0486 resides within the Android permission management system, specifically in the onPackageAddedInternal method of the PermissionManagerService.java component. This flaw represents a critical permissions bypass that allows malicious applications to gain unauthorized access to external storage resources. The vulnerability is particularly concerning because it can be exploited by attackers with only user-level execution privileges, potentially enabling local privilege escalation. The issue affects Android 10 and Android 11 operating systems, making it a widespread concern across multiple Android versions. The Android ID A-171430330 tracks this specific vulnerability within Google's internal tracking system, indicating its recognition as a significant security concern.
The technical implementation of this vulnerability stems from insufficient validation within the PermissionManagerService's package addition handling mechanism. When a new application package is added to the system, the onPackageAddedInternal method fails to properly enforce external storage access restrictions. This creates a window where malicious applications can bypass normal permission checks and gain direct access to shared storage resources. The flaw operates at the system service level, making it particularly dangerous as it can be exploited without requiring user interaction or elevated privileges. The vulnerability essentially allows an application to circumvent the standard Android permission model, enabling unauthorized data access and potential manipulation of external storage contents.
From an operational perspective, this vulnerability poses significant risks to Android device security and user privacy. Attackers could exploit this flaw to access sensitive user data stored on external storage, including documents, photos, videos, and other personal files. The local privilege escalation capability means that even applications with minimal permissions could potentially gain broader system access, creating a pathway for more sophisticated attacks. The implications extend beyond simple data access, as attackers could potentially modify or corrupt stored data, leading to data integrity issues. Additionally, this vulnerability could enable attackers to install malicious components that persist across system reboots, creating long-term security threats for affected devices.
Mitigation strategies for CVE-2021-0486 should focus on both immediate system updates and defensive configuration measures. Organizations and users should prioritize installing the latest Android security patches released by Google, which address this specific permissions bypass vulnerability. System administrators should implement strict application vetting processes and monitor for unauthorized package installations that could exploit this vulnerability. The implementation of application sandboxing measures and enhanced monitoring of external storage access patterns can help detect potential exploitation attempts. Security teams should also consider deploying mobile threat defense solutions that can identify anomalous behavior patterns associated with permission bypass attempts. According to CWE standards, this vulnerability aligns with CWE-284, which addresses improper access control in software systems. The ATT&CK framework categorizes this issue under privilege escalation techniques, specifically targeting the 'Abuse Elevation of Privilege' tactic where adversaries leverage system flaws to gain elevated access rights. Organizations should also consider implementing network-based monitoring to detect potential exploitation attempts and establish incident response procedures specifically designed for this type of local privilege escalation vulnerability.