CVE-2017-8233 in Android
Summary
by MITRE
In a camera driver function in all Android releases from CAF using the Linux kernel, a bounds check is missing when writing into an array potentially leading to an out-of-bounds heap write.
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-8233 represents a critical memory safety issue within the camera driver component of Android systems that utilize the Linux kernel. This flaw exists in all Android releases from the Code Aurora Forum (CAF) and stems from a fundamental failure in input validation mechanisms. The vulnerability specifically manifests in a camera driver function where proper bounds checking has been omitted during array write operations, creating a pathway for potentially exploitable memory corruption.
The technical nature of this vulnerability places it squarely within the realm of buffer overflow conditions, specifically manifesting as an out-of-bounds heap write. This occurs when the camera driver function attempts to write data into an array without verifying that the write operation remains within the allocated memory boundaries. The missing bounds check creates a scenario where attacker-controlled input can cause the driver to write beyond the intended array limits, potentially overwriting adjacent memory locations. This type of vulnerability is classified under CWE-129 as "Improper Validation of Array Index" and represents a classic example of unsafe memory manipulation that can lead to arbitrary code execution.
The operational impact of CVE-2017-8233 extends beyond simple memory corruption, as it provides a potential attack vector for privilege escalation and system compromise. When an out-of-bounds heap write occurs in a kernel driver, the consequences can be severe as the attacker may be able to manipulate critical system structures, overwrite function pointers, or corrupt kernel memory. The camera driver function serves as a privileged execution context within the Linux kernel, making this vulnerability particularly dangerous as it could allow an attacker to gain elevated privileges or cause system instability. The vulnerability affects all Android versions that utilize the CAF kernel, representing a widespread exposure across numerous device models and manufacturers.
From an adversary perspective, this vulnerability aligns with ATT&CK technique T1068 which involves exploiting local privilege escalation opportunities. The attacker would typically need to first gain access to a user-level process that can interact with the camera functionality, then leverage the out-of-bounds write to escalate privileges or execute arbitrary code in kernel space. The exploitation process would involve crafting specific input that triggers the missing bounds check, potentially through malformed camera frame data or manipulated driver parameters. This vulnerability demonstrates the critical importance of input validation in kernel-level components and highlights the need for comprehensive security testing of device drivers.
Mitigation strategies for CVE-2017-8233 must address both immediate remediation and long-term architectural improvements. The primary fix involves implementing proper bounds checking within the camera driver function to validate array indices before write operations occur. Security patches should include bounds verification mechanisms that ensure all array access operations remain within allocated memory limits. Additionally, organizations should implement runtime protections such as stack canaries, address space layout randomization, and kernel address space layout randomization to make exploitation more difficult. The vulnerability underscores the necessity of adhering to secure coding practices and conducting thorough code reviews of kernel components. Device manufacturers should prioritize timely patch deployment and implement robust security testing procedures for all kernel modules, particularly those handling user input or external data streams. This vulnerability serves as a reminder of the critical need for maintaining up-to-date security patches and the importance of comprehensive security assessments for all system components, particularly those operating at kernel level where the impact of memory corruption vulnerabilities can be catastrophic.