CVE-2017-8253 in Android
Summary
by MITRE
In all Qualcomm products with Android releases from CAF using the Linux kernel, kernel memory can potentially be overwritten if an invalid master is sent from userspace.
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Analysis
by VulDB Data Team • 11/09/2019
The vulnerability identified as CVE-2017-8253 represents a critical kernel memory corruption issue affecting Qualcomm Snapdragon chipsets integrated into numerous Android devices. This flaw exists within the Linux kernel implementation used across Qualcomm Android platforms, specifically impacting devices that utilize the Linux kernel version shipped by Qualcomm Android Framework. The vulnerability stems from insufficient validation of master parameters when transmitted from userspace to kernel space, creating a potential pathway for malicious actors to manipulate kernel memory structures. The issue affects all Qualcomm products utilizing Android releases from the Qualcomm Android Framework, making it widespread across various smartphone models, tablets, and other mobile devices that rely on Qualcomm's hardware platforms.
The technical flaw manifests when an invalid master parameter is transmitted from userspace to kernel space, allowing for potential kernel memory overwrite operations. This occurs due to inadequate input validation mechanisms within the kernel's handling of master parameters, which are typically used for device driver communication and hardware abstraction layers. The vulnerability enables an attacker to craft malicious userspace applications that can manipulate kernel memory addresses and potentially overwrite critical kernel structures. This type of memory corruption can lead to arbitrary code execution within kernel space, bypassing standard security mechanisms and potentially allowing full system compromise. The flaw operates at the kernel level where privilege separation between userspace and kernel space is typically maintained, making it particularly dangerous as it can be exploited from unprivileged userspace contexts.
The operational impact of CVE-2017-8253 extends beyond simple memory corruption, as it creates opportunities for privilege escalation and system compromise. Attackers can leverage this vulnerability to gain elevated privileges within the kernel, potentially enabling them to bypass security controls, access sensitive data, or install persistent backdoors. The vulnerability affects devices running Android versions that incorporate Qualcomm's Linux kernel modifications, making it particularly concerning for mobile device security since these platforms represent a significant portion of the global smartphone market. The exploitability of this vulnerability is enhanced by the fact that it requires no special privileges from userspace, as the kernel itself fails to properly validate the master parameter before processing it. This flaw aligns with CWE-125: Out-of-bounds Read and CWE-787: Out-of-bounds Write, representing memory safety issues that can lead to system instability and security breaches.
Mitigation strategies for CVE-2017-8253 primarily focus on patching the kernel implementation to properly validate master parameters before processing them in kernel space. Qualcomm released kernel updates addressing this vulnerability, which should be applied immediately to affected devices. System administrators and device manufacturers should prioritize deploying these patches across all affected Qualcomm Android platforms. Additionally, runtime protections such as kernel address space layout randomization kASLR and stack canaries can help reduce exploitability, though these measures provide only partial protection against this type of vulnerability. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting kernel-level exploits that leverage memory corruption flaws. Organizations should also implement monitoring for suspicious userspace activity that might indicate exploitation attempts, particularly around device driver interfaces and kernel communication channels. Device manufacturers should consider implementing additional input validation at the userspace level to prevent malformed master parameters from reaching kernel space, creating defense-in-depth measures that complement kernel-level patches.