CVE-2023-21176 in Android
Summary
by MITRE • 06/28/2023
In list_key_entries of utils.rs, there is a possible way to disable user credentials due to resource exhaustion. This could lead to local denial of service with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-222287335
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2023-21176 resides within the list_key_entries function in the utils.rs file of Android 13 systems. This flaw represents a critical resource exhaustion issue that can be exploited to disable user credentials and achieve local denial of service conditions. The vulnerability specifically affects Android 13 operating systems with the Android ID A-222287335 and requires system execution privileges for exploitation. The flaw demonstrates characteristics consistent with CWE-400, which addresses resource exhaustion vulnerabilities in software systems. Attackers can leverage this weakness to consume system resources in a manner that renders user authentication mechanisms ineffective.
The technical implementation of this vulnerability stems from improper resource management within the cryptographic key handling utilities. When the list_key_entries function processes key entries, it fails to adequately validate or limit resource consumption during enumeration operations. This deficiency allows malicious actors to craft specific inputs that cause excessive memory allocation or CPU utilization, ultimately leading to system resource exhaustion. The vulnerability operates at the system level, requiring privileged execution context to exploit effectively, which aligns with ATT&CK technique T1499.004 for resource exhaustion attacks. The function's failure to implement proper bounds checking or resource limiting mechanisms creates a pathway for attackers to exhaust available system resources.
The operational impact of CVE-2023-21176 extends beyond simple denial of service conditions to potentially compromise user authentication integrity. When system resources become exhausted through this vulnerability, legitimate user credentials may become inaccessible or disabled, creating a scenario where authorized users cannot authenticate to the system. This credential disabling effect represents a significant security risk as it can effectively lock out legitimate users while potentially providing attackers with persistent access to system resources. The vulnerability's local nature means that exploitation requires physical access or existing system privileges, but once achieved, it can severely disrupt system operations and user access. The resource exhaustion effect can also trigger system instability and may require manual intervention to restore normal operations.
Mitigation strategies for CVE-2023-21176 should focus on implementing robust resource management controls within the cryptographic utilities. System administrators should ensure that the list_key_entries function includes proper input validation, resource consumption limits, and timeout mechanisms to prevent excessive resource allocation. The Android security team has likely implemented patches that address this vulnerability through enhanced bounds checking and resource management within the utils.rs file. Organizations should prioritize applying the latest Android security updates and patches to address this weakness. Additionally, monitoring systems should be configured to detect unusual resource consumption patterns that may indicate exploitation attempts. The vulnerability's classification as a resource exhaustion issue suggests that implementing proper rate limiting and resource allocation controls would provide effective defense against similar attacks. Security professionals should also consider implementing runtime monitoring to detect anomalous behavior in cryptographic key management functions that could indicate exploitation attempts.