CVE-2018-5855 in Android
Summary
by MITRE
While padding or shrinking a nested wmi packet in all Android releases from CAF using the Linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-07-05, a buffer over-read can potentially occur.
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Analysis
by VulDB Data Team • 04/05/2023
The vulnerability identified as CVE-2018-5855 represents a critical buffer over-read flaw within the Android kernel's handling of WMI (Windows Management Instrumentation) packets. This issue affects multiple Android variants including Android for MSM, Firefox OS for MSM, and QRD Android platforms, specifically impacting all versions prior to the security patch level dated 2018-07-05. The vulnerability arises during the processing of nested WMI packets when the system performs padding or shrinking operations on these data structures, creating a scenario where memory access exceeds allocated boundaries.
The technical implementation of this vulnerability stems from improper bounds checking within the kernel's WMI packet handling mechanism. When the system processes nested WMI packets, it attempts to modify the packet size through padding or shrinking operations, but fails to adequately validate the memory boundaries during these transformations. This flaw allows for potential over-read conditions where the kernel accesses memory locations beyond the intended buffer boundaries, potentially exposing sensitive data or enabling arbitrary code execution. The vulnerability is particularly concerning as it exists within the core kernel functionality, making it accessible to both privileged and unprivileged processes that can manipulate WMI packet structures.
From an operational security perspective, this vulnerability presents significant risks to affected Android devices as it could potentially allow attackers to extract confidential information from kernel memory spaces, including cryptographic keys, user credentials, or other sensitive system data. The over-read condition may also provide opportunities for privilege escalation attacks, where malicious actors could leverage the flaw to gain elevated system privileges. Given that this vulnerability affects multiple Android variants and spans several security patch levels, the attack surface is extensive across various device manufacturers and hardware platforms that utilize Qualcomm Snapdragon processors.
The mitigation strategy for CVE-2018-5855 involves applying the security patches released by Google and device manufacturers, specifically targeting the security patch level 2018-07-05 or later. Organizations should implement comprehensive patch management procedures to ensure all affected devices receive the necessary updates. Additionally, network monitoring solutions should be configured to detect anomalous WMI packet processing patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and may be categorized under ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' in the context of kernel-level vulnerabilities. Device manufacturers should also consider implementing additional memory protection mechanisms and runtime checks to prevent similar issues in future implementations.