CVE-2021-1010 in Android
Summary
by MITRE • 12/15/2021
In getSigningKeySet of PackageManagerService.java, there is 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-12Android ID: A-189857801
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-1010 resides within the PackageManagerService.java component of Android 12 systems, specifically in the getSigningKeySet method implementation. This flaw represents a critical permission bypass issue that allows unauthorized local access to sensitive signing key information without requiring any additional execution privileges or user interaction for exploitation. The vulnerability stems from insufficient access controls within the package management service, creating a pathway for malicious actors to extract cryptographic signing keys that are typically protected by proper authorization mechanisms.
The technical flaw manifests as a missing permission check within the getSigningKeySet method, which is responsible for retrieving signing key sets associated with installed applications. This method operates within the core package management service that handles application installation, verification, and security attributes. The absence of proper authorization validation means that any local process running within the Android system can potentially access these sensitive signing key sets. This weakness directly violates the principle of least privilege and creates an information disclosure vulnerability that can be exploited by any application or system component with local access.
From an operational perspective, this vulnerability poses significant security risks as it enables local information disclosure that could facilitate further attacks. An attacker with local access to an Android 12 device could extract signing keys from applications, potentially compromising the integrity verification mechanisms that protect application authenticity. The extracted key information could be used to forge application signatures, bypass security checks, or conduct downgrade attacks against vulnerable applications. Since no additional execution privileges are required and no user interaction is needed, this vulnerability can be exploited automatically by malicious applications or processes running on the same device.
The impact of this vulnerability aligns with CWE-284, which addresses improper access control issues, and represents a clear violation of the Android security model's fundamental principles. The ATT&CK framework categorizes this as a privilege escalation technique through local information disclosure, where attackers can leverage missing permission checks to gain unauthorized access to sensitive system information. This vulnerability affects the entire Android 12 ecosystem and demonstrates the critical importance of proper access control implementation in core system services. The lack of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited silently without detection by standard user awareness mechanisms.
Mitigation strategies should focus on implementing proper permission checks within the getSigningKeySet method and ensuring that all access to signing key information requires appropriate authorization. Android security patches should enforce strict access controls for package management service components, requiring specific permissions such as PACKAGE_USAGE_STATS or similar security attributes before allowing access to signing key sets. System administrators and developers should also consider implementing additional monitoring for unauthorized access attempts to package management services and ensure that proper security auditing is in place to detect potential exploitation attempts. Regular security updates and proper application sandboxing practices are essential to prevent this vulnerability from being leveraged in attack scenarios.