CVE-2023-21373 in Android
Summary
by MITRE • 10/30/2023
In Telephony, there is a possible way for a guest user to change the preferred 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-2023-21373 resides within the telephony subsystem of a mobile operating system, specifically affecting the SIM card management functionality. This issue represents a critical authorization flaw that allows unauthorized users to manipulate cellular preferences without proper authentication. The vulnerability stems from an insufficient permission validation mechanism that fails to properly verify user privileges before permitting changes to SIM card preferences. The flaw exists at the system level where guest user accounts should be restricted from performing administrative functions related to telephony services.
The technical implementation of this vulnerability demonstrates a classic privilege escalation vector through improper access control. When a guest user attempts to modify the preferred SIM card setting, the system fails to perform adequate permission checks that would normally restrict such actions to authenticated administrators or primary users. This missing validation creates an opportunity for privilege elevation without requiring any additional malicious code execution or user interaction. The vulnerability operates at the application programming interface level where telephony services communicate with the underlying operating system kernel components responsible for SIM card management.
From an operational perspective, this vulnerability presents a significant security risk as it enables local privilege escalation with minimal attack surface requirements. An attacker exploiting this flaw can potentially gain elevated system privileges without needing to perform any additional malicious actions beyond accessing the telephony settings interface. The lack of user interaction requirement makes this vulnerability particularly dangerous as it can be exploited automatically without any human intervention. This type of vulnerability directly impacts the principle of least privilege and undermines the security model of the mobile platform.
The security implications extend beyond simple privilege escalation as this vulnerability could potentially enable more sophisticated attacks including unauthorized network access, data interception, or system compromise. According to the CWE taxonomy, this vulnerability aligns with CWE-284 which describes improper access control, and may also relate to CWE-732 which addresses incorrect permission assignment. The ATT&CK framework would categorize this under privilege escalation techniques where adversaries leverage weak access controls to gain elevated system privileges. The vulnerability's impact is amplified by its ability to be exploited locally without network connectivity requirements, making it particularly challenging to detect and prevent through traditional network-based security measures.
Mitigation strategies should focus on implementing robust permission validation mechanisms that enforce strict access controls for telephony management functions. System administrators should ensure that proper user role definitions are implemented to prevent guest accounts from accessing administrative telephony features. The recommended approach involves strengthening the permission checking logic to validate user credentials against appropriate access control lists before allowing any SIM card preference modifications. Additionally, regular security audits should be conducted to identify similar permission gaps in other system components, as this type of vulnerability often indicates broader architectural weaknesses in access control implementation.