CVE-2023-21311 in Android
Summary
by MITRE • 10/30/2023
In Settings, there is a possible way to control private DNS settings from a secondary user due to a permissions bypass. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 10/30/2023
The vulnerability identified as CVE-2023-21311 resides within the Settings application of a mobile operating system, specifically affecting the handling of private DNS configuration parameters. This flaw represents a critical permissions bypass issue that allows unauthorized users to manipulate network security settings without proper authentication or elevated privileges. The vulnerability specifically impacts secondary user accounts on devices where multiple user profiles exist, creating an unexpected pathway for privilege escalation and information disclosure.
The technical root cause of this vulnerability stems from inadequate access control mechanisms within the Settings application's private DNS management functionality. When a secondary user attempts to modify private DNS settings, the system fails to properly validate the user's authorization level, allowing the secondary account to bypass normal security restrictions. This permission bypass occurs at the application level where the system should enforce strict user context boundaries between primary and secondary accounts. The flaw manifests as a missing or insufficient permission check that should validate whether the requesting user has appropriate administrative rights to modify DNS configurations.
The operational impact of this vulnerability extends beyond simple information disclosure to create potential security risks for device users. An attacker with access to a secondary user account could redirect network traffic through malicious DNS servers, potentially enabling man-in-the-middle attacks, credential harvesting, or data exfiltration. Since no user interaction is required for exploitation, this vulnerability can be leveraged automatically without requiring the target user to perform any actions. The lack of additional execution privileges needed means that the attack can be executed entirely through the existing user account without requiring any malicious code installation or privilege escalation techniques. This makes the vulnerability particularly dangerous as it can be exploited silently in the background.
The vulnerability aligns with CWE-284, which addresses improper access control in software applications, and represents a clear violation of the principle of least privilege. From an ATT&CK framework perspective, this vulnerability maps to T1068, which covers "Exploitation for Privilege Escalation" and T1566, which covers "Phishing for Information." The security implications extend to potential network reconnaissance and data interception activities that could compromise user privacy and corporate security. Organizations should consider this vulnerability as a potential entry point for more sophisticated attacks, particularly in environments where multiple user profiles exist and where network security is paramount.
Mitigation strategies should include immediate patch deployment to address the underlying permissions bypass in the Settings application. System administrators should implement monitoring for unauthorized DNS configuration changes and establish network segmentation to limit the impact of potential DNS manipulation. Device manufacturers should review all user context boundaries in their applications to ensure proper access control validation. Additionally, users should be educated about the risks of secondary user accounts and encouraged to maintain strong authentication practices. The vulnerability highlights the importance of comprehensive security testing for multi-user environments and proper validation of access controls in all system components.