CVE-2016-5863 in Android
Summary
by MITRE
In an ioctl handler in all Qualcomm products with Android releases from CAF using the Linux kernel, several sanity checks are missing which can lead to out-of-bounds accesses.
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Analysis
by VulDB Data Team • 12/15/2022
The vulnerability identified as CVE-2016-5863 represents a critical security flaw within the Linux kernel implementation of Qualcomm products running Android versions from the Code Aurora Forum. This issue manifests specifically within an ioctl handler, which serves as a crucial interface for device drivers to communicate with user-space applications. The absence of proper sanity checks in this kernel component creates a pathway for malicious actors to exploit memory access patterns that should otherwise be strictly controlled and validated. The flaw affects a broad range of Qualcomm-based Android devices that utilize kernel versions from the Code Aurora Forum, making it particularly concerning from a widespread impact perspective. This vulnerability falls under the category of improper input validation and memory safety issues, which are fundamental concerns in kernel-level security implementations.
The technical execution of this vulnerability stems from the lack of comprehensive parameter validation within the ioctl handler implementation. When user-space applications interact with kernel drivers through ioctl commands, proper bounds checking should occur to ensure that memory accesses remain within allocated boundaries. Without these essential sanity checks, an attacker can craft malicious ioctl requests that cause the kernel to access memory locations outside of intended buffers or data structures. This out-of-bounds memory access can result in arbitrary code execution, system crashes, or information disclosure, depending on the specific memory regions accessed and the attacker's objectives. The vulnerability is particularly dangerous because it operates at the kernel level where privileges are elevated, allowing for complete system compromise. According to CWE classification, this represents a weakness in the validation of input parameters and memory management practices within kernel drivers, specifically categorized under CWE-129 and CWE-787. The ATT&CK framework would classify this under privilege escalation techniques and kernel-mode exploitation methods, as it enables attackers to gain elevated privileges through kernel-level memory corruption.
The operational impact of CVE-2016-5863 extends beyond simple system instability to encompass potential full system compromise across numerous Qualcomm-based Android devices. Devices utilizing affected kernel versions become vulnerable to attackers who can exploit this flaw to execute arbitrary code with kernel-level privileges, effectively bypassing standard security controls and user access restrictions. This vulnerability affects the integrity and confidentiality of user data, as attackers can potentially read sensitive information from kernel memory or inject malicious code that persists across system reboots. The widespread adoption of Qualcomm chipsets in Android smartphones, tablets, and other mobile devices means that this vulnerability could affect millions of users globally. The exploitability of this issue is particularly concerning given that it requires minimal user interaction to trigger, potentially allowing for remote exploitation through malicious applications or compromised system services. The vulnerability's presence in Code Aurora Forum kernel versions indicates that it affects not only mainstream commercial devices but also those built on open-source kernel implementations that are widely distributed across the mobile ecosystem.
Mitigation strategies for CVE-2016-5863 require immediate attention from device manufacturers and system administrators to address the root cause through kernel patching and code validation. The primary recommendation involves applying official kernel updates from Qualcomm and the Code Aurora Forum that include proper bounds checking and input validation within the affected ioctl handlers. Device manufacturers should prioritize rapid deployment of security patches to their affected product lines, particularly focusing on the kernel components that interface with Qualcomm's proprietary drivers and hardware modules. System administrators should conduct thorough vulnerability assessments to identify all devices running affected kernel versions and implement monitoring solutions to detect potential exploitation attempts. Additionally, organizations should consider implementing runtime protections such as kernel address space layout randomization and stack canaries to make exploitation more difficult. The fix should include comprehensive testing to ensure that the sanity checks do not introduce performance regressions or break existing functionality while providing adequate protection against out-of-bounds memory access. Security teams should also establish incident response procedures specifically addressing kernel-level vulnerabilities to enable rapid response to any exploitation attempts that may occur despite mitigation efforts.