CVE-2017-14878 in Android
Summary
by MITRE
In Android for MSM, Firefox OS for MSM, QRD Android, with all Android releases from CAF using the Linux kernel, a length variable which is used to copy data has a size of only 8 bits and can be exceeded resulting in a denial of service.
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Analysis
by VulDB Data Team • 02/22/2023
This vulnerability exists within the Linux kernel implementations used across various Android platforms including MSM variants, Firefox OS for MSM, and QRD Android systems. The flaw resides in how data copying operations handle length parameters, specifically when an 8-bit variable is employed to store size information that can exceed the maximum value that such a limited data type can accommodate. This represents a classic buffer overflow condition where the size constraint of the length variable creates a scenario where legitimate data operations can cause the system to exceed the bounds of allocated memory regions.
The technical implementation of this vulnerability demonstrates a fundamental flaw in kernel memory management where an 8-bit length variable cannot properly handle the full range of data sizes that might be encountered during legitimate copy operations. When the length parameter exceeds 255 bytes, which is the maximum value an 8-bit unsigned integer can represent, the system experiences a critical failure that manifests as a denial of service condition. This type of vulnerability falls under the CWE-122 vulnerability class, which specifically addresses buffer overflow conditions where insufficient space is allocated for data copying operations.
From an operational perspective, this vulnerability creates a significant risk to system availability and stability across all Android devices utilizing the affected kernel versions from CAF. The denial of service condition can be triggered through various means including malformed network packets, malicious file processing, or other data input scenarios that cause the kernel to attempt copying data exceeding the 8-bit length limit. The impact extends beyond simple system crashes to potentially affecting device functionality and user experience, particularly in mobile environments where system stability is critical for maintaining connectivity and service availability.
The vulnerability's exploitation potential aligns with ATT&CK technique T1499.001, which involves network denial of service attacks that can be achieved through kernel-level vulnerabilities. Organizations should implement immediate mitigation strategies including kernel updates from device manufacturers, network segmentation to limit exposure, and monitoring for abnormal system behavior that might indicate exploitation attempts. Additionally, system administrators should consider implementing defensive measures such as input validation checks and memory protection mechanisms to prevent the exploitation of this specific buffer overflow condition. The vulnerability underscores the importance of proper integer size selection in kernel programming and demonstrates how seemingly minor implementation details can create significant security risks across multiple platform variants.