CVE-2022-26468 in MT6735
Summary
by MITRE • 09/06/2022
In preloader (usb), there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege, for an attacker who has physical access to the device, with no additional execution privileges needed. User interaction is needed for exploitation. Patch ID: ALPS07168125; Issue ID: ALPS07168125.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/14/2022
The vulnerability identified as CVE-2022-26468 resides within the preloader component of USB functionality in Android devices, specifically affecting the bootloader stage that handles USB communication. This represents a critical security flaw that operates at the lowest level of device operation, where the system initializes and prepares for full operating system execution. The preloader serves as a crucial bridge between hardware initialization and the main operating system, making it a prime target for attackers seeking to establish persistent control over device operations.
The technical flaw manifests as a classic out-of-bounds write condition that occurs when the preloader fails to validate input data boundaries during USB communication processing. This missing bounds check allows an attacker to write data beyond the allocated memory buffer, potentially overwriting adjacent memory locations that contain critical system information. The vulnerability specifically impacts the USB preloader module where incoming data from USB connections is processed without adequate validation of buffer limits. This type of flaw falls under CWE-129, which specifically addresses insufficient bounds checking in software implementations.
The operational impact of this vulnerability is particularly severe given that it requires only physical access to the device for exploitation, eliminating the need for network connectivity or additional privileges. An attacker with physical access can manipulate USB input data to trigger the out-of-bounds write condition, potentially allowing local privilege escalation. The requirement for user interaction suggests that the exploitation process may involve specific USB connection sequences or device state changes that must be initiated by the user, but once triggered, the vulnerability can be leveraged to gain elevated system privileges. This aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel or system-level vulnerabilities.
The patch ID ALPS07168125 indicates this was addressed in a specific software update for Android devices, with the issue being resolved through enhanced bounds checking mechanisms in the USB preloader component. This vulnerability demonstrates how low-level bootloader components remain critical attack surfaces, as they operate before the operating system can enforce standard security controls. The fact that exploitation requires physical access but offers privilege escalation makes this a particularly concerning flaw for devices that might be compromised through theft or unauthorized physical access. The vulnerability represents a significant risk to device integrity and user data confidentiality, as successful exploitation could allow attackers to bypass normal security restrictions and gain root-level access to device functions. Organizations should ensure prompt deployment of the ALPS07168125 patch to protect against potential exploitation of this vulnerability in their device fleets.