CVE-2013-6123 in Android-msm
Summary
by MITRE
Multiple array index errors in drivers/media/video/msm/server/msm_cam_server.c in the MSM camera driver for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, allow attackers to gain privileges by leveraging camera device-node access, related to the (1) msm_ctrl_cmd_done, (2) msm_ioctl_server, and (3) msm_server_send_ctrl functions.
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Analysis
by VulDB Data Team • 01/31/2022
The vulnerability described in CVE-2013-6123 represents a critical privilege escalation flaw within the MSM camera driver component of the Linux kernel version 3.x series. This issue affects Qualcomm Innovation Center's Android contributions for MSM devices and extends to various other products utilizing the same kernel components. The vulnerability stems from multiple array index errors that occur within the camera server implementation, specifically within the server/msm_cam_server.c file which serves as the core communication interface between camera applications and the underlying hardware driver. These flaws are particularly concerning because they can be exploited by attackers who already possess access to camera device nodes, which are typically available to applications with camera permissions.
The technical exploitation of this vulnerability occurs through three specific functions within the MSM camera driver: msm_ctrl_cmd_done, msm_ioctl_server, and msm_server_send_ctrl. These functions handle different aspects of camera control commands and server communications, but all suffer from improper array bounds checking that allows attackers to manipulate memory locations through crafted input data. When these functions process user-supplied data, they fail to validate array indices properly, creating opportunities for buffer overflows or out-of-bounds memory access that can be leveraged to execute arbitrary code with elevated privileges. The vulnerability is particularly dangerous because it requires minimal privileges to exploit - attackers only need access to camera device nodes which are typically available to applications with standard camera permissions, making the attack surface significantly broader than typical privilege escalation vulnerabilities.
The operational impact of CVE-2013-6123 is substantial as it allows attackers to escalate privileges from application-level access to kernel-level privileges, effectively bypassing the normal security boundaries of the Android operating system. This privilege escalation capability enables attackers to gain full control over the device, potentially leading to complete system compromise, data theft, or persistent backdoor installation. The vulnerability affects devices running Android versions that incorporate the affected kernel components, which would include numerous smartphones and tablets manufactured by various OEMs using Qualcomm Snapdragon processors. Given that these devices often contain sensitive personal and corporate data, the potential for widespread exploitation and data compromise is significant.
Mitigation strategies for this vulnerability should focus on both immediate patching and broader security hardening measures. The primary solution involves applying the official kernel patches provided by Qualcomm and the Linux kernel maintainers, which address the specific array index errors in the msm_cam_server.c file. Organizations should also implement strict device node access controls, ensuring that camera device nodes are properly restricted to only authorized applications and services. Additionally, system administrators should consider implementing runtime protections such as stack canaries, address space layout randomization, and kernel address space protection mechanisms that can help prevent exploitation even if patches are not immediately available. The vulnerability aligns with CWE-129 which describes improper validation of array indices, and represents a clear example of how driver-level vulnerabilities can be exploited to achieve privilege escalation, falling under ATT&CK technique T1068 for privilege escalation through local exploits.