CVE-2020-0338 in Android
Summary
by MITRE
In AccountManager, there is a possible bypass of a permissions check due to a confused deputy. This could lead to local information disclosure, with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-123700107
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Analysis
by VulDB Data Team • 09/18/2020
The vulnerability identified as CVE-2020-0338 resides within the Android AccountManager component, representing a critical permission bypass flaw that exploits a confused deputy scenario. This issue stems from improper handling of inter-process communication where a malicious application can manipulate the authentication context to gain unauthorized access to account information. The vulnerability specifically affects Android 11 and is tracked under Android ID A-123700107, indicating its classification within Google's security tracking system. The confused deputy problem occurs when a system component incorrectly interprets the identity of the calling process, allowing an attacker to leverage legitimate system permissions to access restricted data.
The technical flaw manifests through improper validation of caller identity within the AccountManager's permission checking mechanisms. When applications attempt to access account information through the system's account management APIs, the permission verification process fails to properly authenticate the actual requesting entity. This creates an opportunity for malicious actors to impersonate legitimate processes and bypass the intended access controls. The vulnerability operates at the system level where account credentials and related information are stored, making it particularly dangerous for information disclosure attacks. The flaw does not require any special privileges beyond what is normally available to applications, and no user interaction is necessary for exploitation to occur.
From an operational impact perspective, this vulnerability enables local information disclosure attacks that can potentially expose sensitive account data including authentication tokens, account names, and associated credentials. Attackers can leverage this bypass to gain access to other applications' account information without requiring additional malicious privileges or user interaction. The implications extend beyond simple data exposure as compromised account information can lead to further exploitation opportunities including account takeovers, data theft, and potential lateral movement within the device. The vulnerability affects the fundamental security model of Android's account management system, undermining the trust relationships between system components and applications.
Mitigation strategies for CVE-2020-0338 should focus on implementing proper caller identity verification within the AccountManager component and strengthening the confused deputy protection mechanisms. System updates and patches from Google address the root cause by correcting the permission checking logic and ensuring proper authentication of calling processes. Organizations should prioritize applying the latest Android security updates and monitor for any signs of exploitation attempts. The vulnerability aligns with CWE-284 which addresses improper access control, and relates to ATT&CK technique T1078 which covers valid accounts for privilege escalation. Additionally, implementing proper application sandboxing and monitoring for unusual account access patterns can help detect potential exploitation attempts. Security teams should also consider the broader implications for Android device security and ensure comprehensive testing of account management APIs following patch deployment to verify the effectiveness of the mitigations.