CVE-2021-25458 in ION driver
Summary
by MITRE • 09/10/2021
NULL pointer dereference vulnerability in ION driver prior to SMR Sep-2021 Release 1 allows attackers to cause memory corruption.
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Analysis
by VulDB Data Team • 09/12/2021
The CVE-2021-25458 vulnerability represents a critical null pointer dereference flaw within the ION driver component of Android systems, specifically affecting versions prior to the SMR September 2021 security release. This vulnerability resides in the kernel-level memory management subsystem that handles buffer allocation and deallocation for graphics and multimedia processing operations. The ION driver serves as a crucial interface for managing shared memory buffers between various system components and applications, making it a prime target for exploitation due to its central role in system memory operations.
The technical implementation of this vulnerability stems from improper validation of memory allocation pointers within the ION driver's buffer management functions. When certain memory allocation requests are processed, the driver fails to properly initialize or validate pointer references before attempting to dereference them, creating a scenario where a null pointer is accessed during memory operations. This flaw typically occurs during the handling of malformed buffer allocation requests or when processing specific combinations of memory management parameters that trigger unexpected code paths within the driver's memory management logic. The vulnerability manifests as a kernel-level crash or memory corruption when the system attempts to access memory locations pointed to by uninitialized or invalid pointers, leading to unpredictable system behavior and potential exploitation.
The operational impact of this vulnerability extends beyond simple system instability, as it provides attackers with a potential pathway for privilege escalation and system compromise. The null pointer dereference can be exploited to cause denial of service conditions that may be leveraged to crash the system or potentially gain elevated privileges within the kernel space. Attackers can craft malicious buffer allocation requests that trigger the vulnerable code path, potentially leading to memory corruption that could be exploited to execute arbitrary code with kernel-level privileges. This vulnerability is particularly concerning in mobile environments where the ION driver interfaces with graphics processing units and multimedia frameworks, as it could be exploited through compromised applications or malicious content processing. The vulnerability aligns with CWE-476 which specifically addresses null pointer dereference conditions, and represents a classic example of how improper pointer validation in kernel drivers can lead to critical security weaknesses.
Mitigation strategies for CVE-2021-25458 primarily focus on applying the vendor-provided security patches released in the SMR September 2021 update, which includes comprehensive fixes for the null pointer dereference issue in the ION driver. System administrators and device manufacturers should prioritize immediate deployment of these patches across affected devices, particularly those running Android versions prior to the patched releases. Additionally, implementing runtime protections such as kernel address space layout randomization and stack canaries can provide additional defense-in-depth measures against exploitation attempts. Network monitoring solutions should be configured to detect anomalous buffer allocation patterns that might indicate exploitation attempts, while application sandboxing and memory protection mechanisms should be enabled to limit the potential impact of successful exploitation. The vulnerability demonstrates the importance of proper input validation and pointer management in kernel-space code, aligning with ATT&CK technique T1068 which covers privilege escalation through kernel exploits, and emphasizing the critical need for robust memory management practices in operating system components. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates and maintain visibility into device security posture through comprehensive vulnerability scanning and monitoring.