CVE-2023-21371 in Android
Summary
by MITRE • 10/30/2023
In Secure Element, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with System 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-2023-21371 resides within the Secure Element component of a system architecture, representing a critical security flaw that could be exploited to achieve local privilege escalation. Secure Elements are hardware-based security components designed to protect sensitive data and cryptographic operations, making this vulnerability particularly concerning as it undermines the fundamental security guarantees these components are intended to provide. The flaw manifests as an integer overflow condition that results in an out-of-bounds write operation, a type of memory corruption vulnerability that has been classified under CWE-190 as an integer overflow or wraparound.
The technical implementation of this vulnerability involves an integer overflow that occurs during arithmetic operations within the Secure Element's processing logic. When an integer exceeds its maximum representable value, it wraps around to the minimum value, creating a scenario where subsequent calculations produce incorrect results. This overflow condition leads to an out-of-bounds write operation where the system attempts to write data beyond the allocated memory boundaries of a buffer or data structure. The vulnerability is particularly dangerous because it can be exploited without requiring user interaction, meaning an attacker with local system access can leverage this flaw to gain elevated privileges. The exploitation requires only system execution privileges, which are typically available to regular users or processes within the system's security model, making the attack surface more accessible than many other privilege escalation vulnerabilities.
The operational impact of CVE-2023-21371 extends beyond simple privilege escalation to potentially compromise the entire security infrastructure of the system. When an attacker successfully exploits this vulnerability, they can execute arbitrary code with system-level privileges, effectively bypassing the security boundaries that the Secure Element is designed to maintain. This could enable unauthorized access to protected cryptographic keys, sensitive data, or critical system functions that should remain isolated from regular user processes. The vulnerability's characteristics align with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation,' and specifically targets the local system's privilege model. The integer overflow condition can be leveraged to overwrite critical system data structures or function pointers, potentially leading to complete system compromise or persistent backdoor access.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and integer overflow protection mechanisms within the Secure Element's codebase. Developers should employ defensive programming practices such as using safe integer arithmetic libraries, implementing bounds checking for all buffer operations, and utilizing compiler flags that detect potential overflow conditions. The fix typically involves correcting the arithmetic operations that lead to the overflow condition, ensuring that integer calculations remain within valid ranges before being used for memory allocation or indexing operations. System administrators should prioritize applying vendor patches and updates as soon as they become available, as this vulnerability can be exploited to gain system-level control. Additionally, implementing runtime protections such as address space layout randomization and stack canaries can provide additional defense-in-depth measures against exploitation attempts. The vulnerability highlights the importance of rigorous security testing and code review processes, particularly for security-critical components like Secure Elements, as these flaws can have cascading effects on the overall system security posture.