CVE-2017-11013 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, countOffset (in function UnpackCore) is increased for each loop, while there is no boundary check against "pIe->arraybound".
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Analysis
by VulDB Data Team • 12/07/2019
This vulnerability exists in Android-based systems utilizing the Linux kernel from Code Aurora Forum with specific releases including MSM, Firefox OS, and QRD Android variants. The flaw manifests within the UnpackCore function where the countOffset variable undergoes incremental increases during loop iterations without proper validation against the arraybound parameter. This represents a classic buffer over-read condition that can lead to memory corruption and potential system exploitation. The vulnerability is particularly concerning as it affects multiple Android variants and embedded systems that rely on the Linux kernel for their core operations.
The technical implementation of this flaw demonstrates a fundamental lack of input validation within the unpacking routine. When processing data structures, the countOffset variable accumulates values from each iteration without verifying whether it exceeds the allocated array boundaries defined by pIe->arraybound. This absence of boundary checking creates a scenario where memory locations beyond the intended array limits can be accessed and modified, potentially leading to arbitrary code execution or system instability. The vulnerability operates at the kernel level, making it particularly dangerous as it can affect system stability and security across multiple device types.
The operational impact of CVE-2017-11013 extends beyond simple memory corruption, as it can enable attackers to execute malicious code with kernel-level privileges. This vulnerability aligns with CWE-129, which addresses insufficient input validation, and represents a specific instance of improper boundary checking in array access operations. The flaw can be exploited through carefully crafted data inputs that manipulate the unpacking process, potentially allowing attackers to gain unauthorized access to system resources, modify critical memory areas, or cause denial of service conditions. Systems utilizing affected Android variants become susceptible to attacks that leverage this memory access violation.
Mitigation strategies should focus on implementing proper boundary checks within the UnpackCore function to validate countOffset against arraybound parameters before incrementing. Organizations should prioritize applying security patches from their respective vendors, including Code Aurora Forum and device manufacturers who distribute affected Android variants. The implementation of address space layout randomization and stack canaries can provide additional defense-in-depth measures. From an ATT&CK framework perspective, this vulnerability maps to T1068, which covers the exploitation of remote services, and T1059, involving the execution of malicious code through system processes. Regular security audits and code reviews focusing on input validation and memory management practices are essential for preventing similar vulnerabilities in future implementations.