CVE-2014-0206 in Linux
Summary
by MITRE
Array index error in the aio_read_events_ring function in fs/aio.c in the Linux kernel through 3.15.1 allows local users to obtain sensitive information from kernel memory via a large head value.
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Analysis
by VulDB Data Team • 08/09/2021
The vulnerability identified as CVE-2014-0206 represents a critical array index error within the Linux kernel's asynchronous I/O subsystem, specifically in the aio_read_events_ring function located in fs/aio.c. This flaw exists in kernel versions through 3.15.1 and affects the core functionality of the kernel's asynchronous I/O implementation. The vulnerability arises from insufficient bounds checking when processing large head values, creating a potential information disclosure mechanism that could expose sensitive kernel memory contents to unprivileged local users. The affected code path processes asynchronous I/O events and maintains an internal ring buffer structure that tracks completed operations, making this a fundamental flaw in the kernel's memory management and access control mechanisms.
The technical exploitation of this vulnerability occurs when a local user crafts a malicious asynchronous I/O operation with an excessively large head value, causing the aio_read_events_ring function to access array elements beyond the allocated memory boundaries. This array index error leads to a memory access violation that can result in kernel memory disclosure, where the kernel's internal data structures, potentially containing sensitive information such as cryptographic keys, passwords, or other confidential data, become accessible to the local attacker. The flaw stems from a lack of proper input validation and boundary checking, allowing an attacker to manipulate the indexing logic and read arbitrary kernel memory locations. This type of vulnerability falls under CWE-129, which specifically addresses insufficient validation of array indices, and represents a classic case of improper input validation leading to memory corruption.
The operational impact of CVE-2014-0206 extends beyond simple information disclosure, as it provides local attackers with the ability to extract potentially sensitive kernel data that could be used in subsequent attacks. The vulnerability is particularly concerning because it requires no special privileges beyond standard user access, making it an attractive target for attackers seeking to escalate their privileges or gather intelligence about the target system. The exposure of kernel memory can reveal information about kernel data structures, memory layout details, and potentially sensitive cryptographic material, which could be leveraged to bypass security mechanisms or develop more sophisticated attacks. This vulnerability directly impacts the kernel's security model and can undermine the isolation guarantees that separate user space processes from kernel space operations, creating potential pathways for privilege escalation or information leakage that violates fundamental security principles.
Mitigation strategies for CVE-2014-0206 primarily involve applying the official kernel patches released by the Linux kernel development team, which address the array index validation issue by implementing proper bounds checking in the aio_read_events_ring function. System administrators should prioritize updating to kernel versions 3.15.2 or later, where the vulnerability has been resolved through enhanced input validation and proper array boundary checks. Additional protective measures include implementing strict access controls, monitoring for unusual asynchronous I/O patterns, and employing kernel hardening techniques such as stack canaries and address space layout randomization to complicate exploitation attempts. Security teams should also consider implementing intrusion detection systems that can identify potential exploitation attempts based on anomalous head value patterns in asynchronous I/O operations, aligning with ATT&CK technique T1059.001 for command and scripting interpreter usage patterns. The vulnerability demonstrates the critical importance of proper input validation in kernel code and serves as a reminder of how seemingly minor boundary checking flaws can result in significant security implications across the entire system security model.