CVE-2023-21393 in Android
Summary
by MITRE • 10/30/2023
In Settings, there is a possible way for the user to change SIM due to a missing permission check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/22/2023
The vulnerability identified as CVE-2023-21393 resides within the Settings application component of a mobile operating system, specifically targeting the SIM card management functionality. This flaw represents a critical permission oversight that allows unauthorized modification of SIM-related settings without proper authentication or authorization checks. The vulnerability manifests when the system fails to validate whether the requesting process possesses adequate privileges before permitting SIM configuration changes, creating a potential pathway for privilege escalation attacks.
The technical implementation of this vulnerability stems from inadequate access control mechanisms within the Settings application's SIM management module. When users attempt to modify SIM settings through the graphical interface or programmatic interfaces, the system should verify that the calling process has elevated privileges or proper user authentication before executing the requested changes. However, the missing permission check allows any application or process with access to the Settings API to modify SIM configurations without proper authorization. This flaw aligns with CWE-284, which describes improper access control vulnerabilities where insufficient checks prevent unauthorized access to protected resources. The vulnerability operates at the system level where SIM card configuration changes can potentially grant malicious actors access to cellular network services, location tracking capabilities, or other sensitive communications functions that are typically restricted to system-level processes or authenticated users.
The operational impact of this vulnerability extends beyond simple configuration changes, as it enables local privilege escalation without requiring additional execution privileges or user interaction. Attackers can exploit this weakness to gain elevated system privileges by manipulating SIM settings, potentially allowing them to access restricted system functions, modify critical system parameters, or establish persistent access to the device. The lack of user interaction requirement makes this vulnerability particularly dangerous as it can be exploited automatically through malicious applications or scripts without any human intervention. This characteristic places the vulnerability in the ATT&CK framework under T1068, which covers "Local Privilege Escalation" and specifically addresses techniques that allow adversaries to elevate their privileges on a compromised system. The vulnerability affects the integrity and confidentiality of the device's security model, as it undermines the fundamental principle of least privilege that should govern access to sensitive system functions.
Mitigation strategies for CVE-2023-21393 should focus on implementing robust permission validation mechanisms within the Settings application and ensuring that all SIM-related configuration changes require proper authentication and authorization. System administrators and device manufacturers should prioritize patching the vulnerability through official software updates that enforce proper access controls before allowing SIM configuration modifications. Additional protective measures include monitoring for unauthorized SIM changes through system logs, implementing application whitelisting to restrict which applications can access SIM management APIs, and conducting regular security audits of system components to identify similar permission gaps. The vulnerability highlights the importance of comprehensive security testing of system-level interfaces and the need for proper input validation and access control checks in all components that handle sensitive device configurations. Organizations should also consider implementing network monitoring solutions to detect suspicious SIM-related activities that might indicate exploitation attempts, as the vulnerability could be leveraged for more sophisticated attacks including data exfiltration or device compromise.