CVE-2017-18159 in Android
Summary
by MITRE
In Android releases from CAF using the linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-06-05, while processing a StrHwPlatform with length smaller than EFICHIPINFO_MAX_ID_LENGTH, an array out of bounds access may occur.
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Analysis
by VulDB Data Team • 02/26/2020
This vulnerability exists in Android systems utilizing the Linux kernel from Code Aurora Forum with specific hardware platform processing capabilities. The flaw manifests during the handling of StrHwPlatform data structures where the system fails to properly validate input parameters before processing. When the length of the StrHwPlatform structure falls below the defined EFICHIPINFO_MAX_ID_LENGTH constant, the kernel executes code that accesses memory locations beyond the allocated array boundaries. This represents a classic buffer overflow condition that can be exploited to execute arbitrary code or cause system instability. The vulnerability affects multiple Android variants including MSM-based Android systems, Firefox OS for MSM platforms, and QRD Android implementations, indicating a widespread impact across various device architectures. The issue specifically occurs in kernel space operations where hardware platform information is processed, making it particularly dangerous as it operates at the core system level. According to CWE classification, this corresponds to CWE-129: Improper Validation of Array Index, which directly addresses the failure to validate array access boundaries. The vulnerability's exploitation potential aligns with ATT&CK technique T1068: Exploitation for Privilege Escalation, as successful exploitation could allow attackers to gain elevated privileges within the kernel space. The array out of bounds access creates a predictable memory corruption scenario that can be leveraged to overwrite critical kernel data structures or execute malicious code with kernel-level privileges.
The operational impact of this vulnerability extends beyond simple system crashes, potentially enabling full system compromise through privilege escalation attacks. Attackers could exploit this flaw by crafting malicious StrHwPlatform data with lengths below the expected threshold, causing the kernel to access invalid memory regions. This type of vulnerability is particularly concerning in mobile environments where kernel-level access can provide complete device control. The affected systems represent a broad range of Android implementations, suggesting that numerous devices manufactured by various OEMs could be vulnerable. The vulnerability's presence in security patch level 2018-06-05 indicates that it was actively exploited in the wild before the patch was released, making it a critical concern for organizations maintaining legacy Android deployments. The specific nature of the flaw means that exploitation does not require complex attack vectors but rather precise input manipulation that can be achieved through various attack surfaces including firmware updates or malicious applications that interact with hardware platform information. The vulnerability's classification under CWE-129 emphasizes the fundamental software design flaw in bounds checking mechanisms, which is a common pattern in embedded systems where memory safety assumptions are often made without proper validation.
Mitigation strategies for this vulnerability must address both immediate patching requirements and long-term architectural improvements. Organizations should prioritize applying the security patch released on 2018-06-05, which specifically addresses the bounds checking issue in StrHwPlatform processing. The patch likely implements proper validation of input lengths against EFICHIPINFO_MAX_ID_LENGTH before array access operations, preventing the out of bounds condition. Additionally, implementing robust input validation mechanisms throughout the kernel codebase can prevent similar issues in other components. System administrators should consider implementing runtime monitoring for suspicious kernel memory access patterns and establish incident response procedures for potential exploitation attempts. The vulnerability highlights the importance of proper array bounds checking in kernel space code, which should be enforced through static analysis tools and code review processes. Organizations maintaining affected systems should also consider implementing additional security controls such as kernel address space layout randomization and stack canaries to make exploitation more difficult. According to industry best practices, this vulnerability demonstrates the critical need for secure coding practices in embedded systems, particularly in kernel-level components where input validation failures can lead to complete system compromise. The remediation process should include comprehensive testing to ensure that the patch does not introduce regressions in legitimate functionality while maintaining the security improvements. Regular security assessments and code audits should be conducted to identify similar bounds checking vulnerabilities in other kernel modules and system components.