CVE-2016-4038 in Phone
Summary
by MITRE
Array index error in the msm_sensor_config function in kernel/SM-G9008V_CHN_KK_Opensource/Kernel/drivers/media/platform/msm/camera_v2/sensor/msm_sensor.c in Samsung devices with Android KK(4.4) or L and an APQ8084, MSM8974, or MSM8974pro chipset allows local users to have unspecified impact via the gpio_config.gpio_name value.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/31/2020
The vulnerability identified as CVE-2016-4038 represents a critical array index error within the msm_sensor_config function of Samsung's Android kernel implementation for specific device models. This flaw exists in the kernel source code located at kernel/SM-G9008V_CHN_KK_Opensource/Kernel/drivers/media/platform/msm/camera_v2/sensor/msm_sensor.c, affecting Samsung devices running Android KitKat 4.4 or Lollipop with Qualcomm APQ8084, MSM8974, or MSM8974pro chipsets. The vulnerability stems from improper validation of the gpio_config.gpio_name value parameter, which creates a predictable array indexing issue that can be exploited by local attackers with kernel-level privileges.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of array indices, and represents a classic buffer overflow condition that occurs when an attacker can manipulate input parameters to access memory locations outside the bounds of allocated arrays. The msm_sensor_config function processes GPIO configuration data without adequate bounds checking on the gpio_name parameter, allowing an attacker to provide an invalid index value that results in memory corruption. This specific implementation flaw affects the camera subsystem's sensor configuration mechanism, where GPIO pin assignments are managed through a structured data approach that relies on indexed arrays for configuration parameters.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with the ability to manipulate camera hardware configuration at the kernel level. Local users with access to the device can potentially cause system instability, crash the camera subsystem, or more critically, gain unauthorized access to sensitive camera hardware components. The vulnerability's exploitation could result in persistent system compromise, as it allows for manipulation of hardware configuration that may be used for privilege escalation or persistent backdoor creation. Attackers could leverage this issue to establish persistent access to device camera hardware, potentially enabling surveillance capabilities or further system compromise through exploitation of other related components.
Security mitigations for this vulnerability should focus on implementing proper array bounds checking within the msm_sensor_config function and ensuring that all input parameters undergo rigorous validation before being used as array indices. The fix should include input sanitization of the gpio_config.gpio_name value to prevent out-of-bounds memory access and proper error handling for invalid input values. Organizations should also implement kernel hardening measures including stack canaries, address space layout randomization, and kernel module protection mechanisms to reduce the overall exploitability of such vulnerabilities. Additionally, regular security audits of kernel source code implementations should be conducted to identify similar array indexing issues, particularly in hardware abstraction layers and device driver code that handle user-supplied data for hardware configuration. The vulnerability demonstrates the importance of secure coding practices in kernel development environments and highlights the need for comprehensive input validation in all system components that interact with hardware configuration parameters, particularly those that operate at the kernel level where privilege escalation can lead to complete system compromise.