CVE-2015-7892 in m2m1shot Driver Framework
Summary
by MITRE
Stack-based buffer overflow in the m2m1shot_compat_ioctl32 function in the Samsung m2m1shot driver framework, as used in Samsung S6 Edge, allows local users to have unspecified impact via a large data.buf_out.num_planes value in an ioctl call.
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Analysis
by VulDB Data Team • 06/08/2024
The vulnerability identified as CVE-2015-7892 represents a critical stack-based buffer overflow within the Samsung m2m1shot driver framework, specifically affecting the m2m1shot_compat_ioctl32 function. This flaw exists within the kernel-level device driver implementation that manages multimedia processing operations on Samsung mobile devices, particularly impacting the Samsung S6 Edge model. The vulnerability stems from inadequate input validation mechanisms within the driver's compatibility ioctl handling routine, which processes 32-bit ioctl calls on 64-bit systems. The m2m1shot driver framework serves as a multimedia processing interface that handles various image and video processing operations, making it a prime target for exploitation due to its privileged execution context and direct hardware access capabilities.
The technical implementation of this vulnerability occurs when the m2m1shot_compat_ioctl32 function processes ioctl commands without proper bounds checking on the data.buf_out.num_planes parameter. This parameter controls the number of planes in a buffer structure that the driver uses to manage multimedia data processing. When an attacker supplies an excessively large value for num_planes, the driver's stack allocation logic fails to validate the input size, leading to a buffer overflow condition where data written to the stack exceeds the allocated buffer boundaries. This overflow can overwrite adjacent stack variables, function return addresses, and other critical execution context information, potentially enabling arbitrary code execution. The vulnerability is classified under CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it provides attackers with the capability to execute arbitrary code within the kernel context of the Samsung S6 Edge device. Since the m2m1shot driver operates with elevated privileges and has direct access to multimedia hardware components, successful exploitation could enable attackers to manipulate camera functionality, access sensitive multimedia data, or potentially compromise the entire device. The unspecified nature of the impact reflects the broad range of potential consequences that could arise from such a kernel-level vulnerability, including but not limited to persistent backdoor installation, data exfiltration, or complete device takeover. This vulnerability falls under the ATT&CK framework's privilege escalation techniques, specifically targeting kernel-level attack vectors that leverage device driver weaknesses to gain elevated system privileges.
Mitigation strategies for CVE-2015-7892 require immediate implementation of firmware updates from Samsung that address the buffer overflow in the m2m1shot driver framework. System administrators should ensure that all affected Samsung S6 Edge devices receive the latest security patches, as these updates typically include input validation fixes and stack buffer size restrictions. Additionally, implementing kernel hardening techniques such as stack canaries, address space layout randomization, and kernel address space protection can provide defense-in-depth measures against exploitation attempts. Network monitoring solutions should be configured to detect unusual ioctl call patterns that might indicate exploitation attempts, while device management systems should enforce strict firmware version controls to prevent deployment of vulnerable device drivers. Organizations should also consider implementing runtime application control measures and regular security assessments to identify potential exploitation vectors that could leverage similar driver-based vulnerabilities in other multimedia processing components.