CVE-2017-15821 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, in the function wma_p2p_noa_event_handler(), there is no bound check on a value coming from firmware which can potentially lead to a buffer overwrite.
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Analysis
by VulDB Data Team • 02/22/2023
The vulnerability identified as CVE-2017-15821 represents a critical buffer overflow flaw within the Android kernel implementation for Qualcomm MSM devices. This issue affects multiple Android variants including CAF Android, Firefox OS for MSM, and QRD Android releases that utilize the Linux kernel. The vulnerability stems from inadequate input validation within the wireless media access layer function wma_p2p_noa_event_handler() which processes events related to peer-to-peer networking. The flaw occurs when the function receives data from firmware without performing proper bounds checking on values that could potentially exceed allocated buffer boundaries. This particular implementation fails to validate the size or content of incoming firmware data before using it to determine buffer operations.
The technical exploitation of this vulnerability can result in arbitrary code execution within the kernel context, providing attackers with elevated privileges to manipulate system memory and potentially gain full device control. The absence of bounds checking creates an environment where malicious firmware or attacker-controlled data can cause memory corruption through buffer overflows. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though it manifests in kernel space rather than user space. The attack surface is particularly concerning as it operates at the kernel level where memory corruption can lead to complete system compromise and persistent backdoor access.
Operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass full system takeover capabilities. Attackers could leverage this flaw to execute malicious code with kernel-level privileges, potentially enabling them to bypass security mechanisms, install rootkits, or establish persistent access points. The vulnerability affects devices that rely on Qualcomm MSM chipsets and the associated Linux kernel implementations, making it particularly relevant for mobile devices, IoT systems, and embedded platforms utilizing these components. The exploitation requires minimal privileges since the flaw exists within kernel-level firmware handling code, making it especially dangerous in environments where firmware updates are infrequent or not properly managed.
Mitigation strategies for CVE-2017-15821 should prioritize immediate firmware and kernel updates from device manufacturers and Qualcomm. System administrators should implement firmware integrity checking mechanisms and monitor for unauthorized firmware modifications. The vulnerability aligns with ATT&CK technique T1068 which involves privilege escalation through kernel exploits, making it a significant concern for threat actors seeking persistent access. Device manufacturers should enforce proper input validation in all kernel functions that process external data, implementing robust bounds checking mechanisms. Additionally, memory protection features such as stack canaries, address space layout randomization, and kernel address space layout randomization should be enabled to complicate exploitation attempts. Organizations should also consider network segmentation and monitoring for unusual firmware communication patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of secure coding practices in kernel development and the necessity of thorough input validation mechanisms to prevent buffer overflow conditions.