CVE-2023-21178 in Android
Summary
by MITRE • 06/28/2023
In installKey of KeyUtil.cpp, there is a possible failure of file encryption due to a race condition. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-140762419
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2023-21178 resides within the installKey function of KeyUtil.cpp in Android 13 systems, representing a critical race condition that compromises file encryption integrity. This flaw manifests during the key installation process where concurrent access to cryptographic resources creates an exploitable window where encryption operations may fail or become compromised. The race condition occurs when multiple threads or processes attempt to manipulate key storage or encryption parameters simultaneously, leading to unpredictable outcomes in the cryptographic operations that protect sensitive data. The vulnerability requires system-level execution privileges for exploitation, indicating that an attacker must already possess elevated permissions to leverage this weakness effectively. However, the nature of the race condition means that even with system privileges, the timing of operations can create scenarios where encryption fails to properly secure data, potentially exposing sensitive information.
The technical implementation of this vulnerability stems from improper synchronization mechanisms within the key management system, where shared resources such as key storage locations, encryption parameters, or cryptographic context variables are accessed without adequate locking mechanisms. When the installKey function processes key installation requests, it fails to properly coordinate access to these critical resources, allowing for concurrent modifications that can corrupt encryption keys or prevent proper encryption from occurring. This race condition typically occurs in multi-threaded environments where the system's key management service handles multiple concurrent requests for key installation or modification. The flaw aligns with CWE-362, which specifically addresses race conditions in concurrent programming environments, and represents a classic example of improper resource management in cryptographic systems where temporal dependencies create security vulnerabilities. The vulnerability's impact extends beyond simple encryption failure, as it can lead to complete information disclosure when encryption processes are bypassed or corrupted due to the concurrent access patterns.
From an operational perspective, this vulnerability poses significant risks to Android 13 devices where system-level privileges are already compromised or obtained through other attack vectors. The local information disclosure threat means that sensitive data stored in encrypted formats could be exposed to unauthorized access, potentially including user credentials, personal information, application data, or system configuration details. Attackers who can execute code with system privileges can exploit this race condition to systematically bypass encryption protections, particularly when multiple encryption operations are occurring simultaneously. The vulnerability's exploitation does not require user interaction, making it particularly dangerous as it can be triggered automatically during normal system operations or through carefully timed attacks that manipulate the timing of encryption processes. This characteristic places the vulnerability in the ATT&CK framework under T1059.003 for execution through system commands and T1566.001 for initial access through system-level privileges. The impact is amplified because encryption failures can result in cascading security issues where multiple encrypted data stores become accessible, potentially exposing large volumes of sensitive information.
Mitigation strategies for CVE-2023-21178 should focus on implementing proper synchronization mechanisms within the key management system to prevent concurrent access to critical cryptographic resources. The most effective approach involves adding mutex locks or other thread synchronization primitives around the key installation operations in KeyUtil.cpp to ensure that only one process can modify key storage or encryption parameters at any given time. Additionally, developers should implement proper error handling and validation checks to detect when encryption operations fail due to race conditions and ensure that such failures result in secure error states rather than partial or corrupted encryption. System administrators should prioritize applying security patches from Android 13 updates that address this specific race condition, as these updates typically include improved synchronization mechanisms and enhanced cryptographic operation validation. Organizations should also implement monitoring solutions to detect unusual patterns of key installation requests or encryption failures that might indicate exploitation attempts. The vulnerability highlights the importance of robust concurrent programming practices in cryptographic systems and demonstrates how seemingly minor synchronization issues can create significant security weaknesses. Security teams should conduct thorough testing of key management operations under concurrent access scenarios to identify similar race conditions in other cryptographic components, as the underlying architectural issue affects the entire key management subsystem rather than just the specific installKey function.