CVE-2023-21364 in Android
Summary
by MITRE • 10/30/2023
In ContactsProvider, there is a possible crash loop due to resource exhaustion. This could lead to local persistent denial of service in the Phone app with User execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/24/2023
The vulnerability identified as CVE-2023-21364 resides within the ContactsProvider component of Android systems, representing a critical resource exhaustion flaw that can trigger persistent denial of service conditions. This issue specifically affects the Phone application where malicious actors can exploit the vulnerability to cause repeated system crashes and restart cycles. The flaw operates at the system level where insufficient resource management allows an attacker with user execution privileges to consume available system resources until the device becomes unresponsive. The vulnerability is particularly concerning because it does not require user interaction for exploitation, making it an automated threat vector that can be triggered remotely or through pre-existing system access.
The technical implementation of this vulnerability stems from inadequate resource handling within the ContactsProvider subsystem, which manages contact data and synchronization functions. When the system processes certain contact data structures or performs specific operations on contact records, it fails to properly validate resource consumption limits or implement adequate cleanup procedures. This allows an attacker to craft malicious contact entries or trigger specific processing paths that cause the system to continuously allocate resources without proper deallocation, leading to progressive resource depletion. The flaw operates at the application level but affects system stability through the Phone app's dependency on ContactsProvider for contact information display and management functions.
The operational impact of CVE-2023-21364 extends beyond simple service disruption to create persistent system instability that can render devices unusable for extended periods. Once exploited, the vulnerability creates a crash loop that continuously restarts the affected system components, preventing normal phone functionality and potentially causing data loss or corruption. The persistent nature of this denial of service means that even after initial exploitation attempts, the system remains vulnerable until the underlying resource exhaustion is resolved through manual intervention or system reboot. This vulnerability particularly affects mobile devices where the Phone app is frequently used and where contact data synchronization occurs regularly, making it a significant threat to device availability and user productivity.
From a cybersecurity perspective, this vulnerability aligns with CWE-400, which addresses resource exhaustion issues in software systems, and maps to attack patterns within the ATT&CK framework under the T1499.1 sub-technique for network denial of service. The vulnerability demonstrates how insufficient input validation and resource management can create persistent threats that do not require user interaction, making them particularly dangerous in environments where mobile devices serve critical communication functions. Organizations should implement immediate mitigations including system updates from vendors, monitoring for abnormal resource consumption patterns, and potential temporary disabling of contact synchronization features until patches are deployed.
The remediation approach for CVE-2023-21364 requires both immediate and long-term security measures to address the root cause of resource exhaustion. System administrators should prioritize applying vendor security patches as soon as they become available, while also implementing monitoring solutions that can detect unusual resource consumption patterns that might indicate exploitation attempts. Additional mitigations include implementing resource quotas for system components, enhancing input validation procedures for contact data processing, and establishing automated alerting mechanisms for system stability issues. Organizations should also consider network-level controls that can limit the scope of potential exploitation and implement regular security assessments to identify similar resource management vulnerabilities in other system components. The vulnerability serves as a reminder of the critical importance of proper resource management in system design and the potential for seemingly minor implementation flaws to create significant operational disruptions.