CVE-2018-3579 in Android
Summary
by MITRE
In the WLAN driver in all Android releases from CAF (Android for MSM, Firefox OS for MSM, QRD Android) using the Linux Kernel, event->num_entries_in_page is a value received from firmware that is not properly validated which can lead to a buffer over-read
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Analysis
by VulDB Data Team • 02/18/2020
The vulnerability identified as CVE-2018-3579 represents a critical buffer over-read flaw within the wireless local area network driver component of Android systems. This issue affects all Android releases utilizing the Linux kernel from Qualcomm Automotive Framework, including Android for MSM, Firefox OS for MSM, and QRD Android platforms. The vulnerability stems from improper validation of a critical parameter received from the firmware component, specifically the event->num_entries_in_page field which serves as a crucial indicator for memory allocation and data processing within the wireless driver subsystem. The flaw exists in the communication channel between the hardware firmware and the software driver, creating a potential pathway for malicious actors to exploit the system's memory management mechanisms.
The technical execution of this vulnerability involves the wireless driver receiving an unvalidated integer value from firmware that determines how many entries should be processed from a memory page. When this value exceeds the actual allocated buffer space or falls below acceptable thresholds, the driver performs memory operations that extend beyond the intended boundaries. This over-read condition can result in the driver accessing memory locations that do not belong to the intended data structure, potentially exposing sensitive information or causing system instability. The flaw operates at the kernel level within the Linux kernel's wireless subsystem, making it particularly dangerous as it can be exploited to gain unauthorized access to system memory or cause denial of service conditions. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though in this specific case it manifests as an over-read rather than a traditional overflow condition.
The operational impact of CVE-2018-3579 extends beyond simple system instability to encompass potential information disclosure and privilege escalation scenarios. An attacker capable of manipulating the firmware communication or exploiting a related vulnerability could trigger the over-read condition to extract sensitive data from kernel memory, including cryptographic keys, user credentials, or other confidential information. The vulnerability affects devices running various Android versions and hardware platforms, making it a widespread concern across the mobile ecosystem. This flaw can be leveraged in conjunction with other attack vectors to create more sophisticated exploitation chains, potentially enabling attackers to execute arbitrary code within the kernel context or gain elevated privileges on the affected devices. The attack surface includes both local and remote exploitation scenarios depending on the specific implementation and device configuration.
Mitigation strategies for CVE-2018-3579 should focus on implementing proper input validation mechanisms within the wireless driver component to ensure all values received from firmware are strictly validated before processing. System administrators and device manufacturers should prioritize applying security patches and firmware updates that include bounds checking for the event->num_entries_in_page parameter. The implementation of memory protection mechanisms such as stack canaries, address space layout randomization, and kernel address space layout randomization should be enabled to reduce the effectiveness of exploitation attempts. Additionally, monitoring and logging of wireless driver operations can help detect anomalous behavior indicative of exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit the potential attack surface and prevent unauthorized access to wireless communication channels. The vulnerability demonstrates the critical importance of proper input validation in kernel-level drivers and highlights the need for comprehensive security testing of firmware-to-software interfaces. This issue aligns with ATT&CK technique T1068 which covers local privilege escalation and T1566 which involves credential access through network infrastructure, emphasizing the multi-faceted nature of the threat posed by such kernel-level vulnerabilities.