CVE-2018-5828 in Android
Summary
by MITRE
In Qualcomm Android for MSM, Firefox OS for MSM, and QRD Android with all Android releases from CAF using the Linux kernel before security patch level 2018-04-05, in function wma_extscan_start_stop_event_handler(), vdev_id comes from the variable event from firmware and is not properly validated potentially leading to a buffer overwrite.
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Analysis
by VulDB Data Team • 01/21/2020
The vulnerability identified as CVE-2018-5828 represents a critical buffer overflow flaw within the wireless media access layer of Qualcomm's Android and Firefox OS implementations. This issue manifests in the wma_extscan_start_stop_event_handler() function where the vdev_id parameter is sourced directly from firmware events without adequate validation mechanisms. The flaw exists across multiple Qualcomm platforms including MSM, Firefox OS for MSM, and QRD Android systems, affecting all Android releases from the Common Audio Framework through the specified security patch level of April 5, 2018. The vulnerability stems from insufficient input validation practices that allow maliciously crafted firmware events to manipulate the vdev_id value, potentially enabling attackers to overwrite adjacent memory regions in the kernel space.
The technical exploitation of this vulnerability occurs through a classic buffer overflow scenario where unvalidated firmware input directly influences memory access patterns within the wireless subsystem. When the function processes the event structure containing the vdev_id variable, the lack of proper bounds checking allows an attacker to provide an invalid or oversized vdev_id value that exceeds the allocated buffer boundaries. This condition creates opportunities for arbitrary code execution within kernel space, as the overflow can overwrite critical function pointers, return addresses, or other control data structures essential for maintaining system integrity. The vulnerability is particularly concerning because it operates at the kernel level where successful exploitation can result in complete system compromise and persistent access to the device.
From an operational perspective, this vulnerability poses significant risks to mobile device security across the Qualcomm ecosystem, particularly affecting devices running Android versions from the Common Audio Framework era through the targeted patch level. The attack surface is broad as it impacts multiple Qualcomm platforms including various smartphone models, tablets, and IoT devices that rely on Qualcomm's wireless chipsets. The exploitation potential aligns with ATT&CK technique T1059.007 for command and control operations and T1068 for privilege escalation, as successful exploitation can lead to root-level access and persistent backdoor installation. The vulnerability's classification under CWE-121 indicates a direct buffer overflow condition that can be leveraged for memory corruption attacks, while its kernel-level nature places it within the high-impact category of security flaws that can result in complete system compromise without user interaction.
Mitigation strategies for CVE-2018-5828 must prioritize immediate patch deployment to the affected security patch level of April 5, 2018, or equivalent updates that address the input validation deficiencies in the wma_extscan_start_stop_event_handler() function. Organizations should implement firmware validation mechanisms that enforce strict bounds checking on all firmware-provided parameters, particularly those related to wireless subsystem identifiers. The implementation of kernel address space layout randomization and stack canaries can provide additional defense-in-depth measures against exploitation attempts. Security monitoring should focus on anomalous wireless scanning behavior and unexpected firmware event processing patterns that might indicate exploitation attempts. Device manufacturers should also consider implementing runtime integrity checks and firmware signature verification to prevent unauthorized modifications that could leverage this vulnerability. The vulnerability highlights the importance of proper input validation practices and the need for robust kernel security mechanisms that protect against memory corruption attacks, particularly within wireless communication subsystems that handle untrusted firmware inputs.