CVE-2026-20582 in MT6993
Summary
by MITRE • 11/02/2026
In usb, there is a possible memory corruption due to double free. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11411924; Issue ID: MSV-9748.
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Analysis
by VulDB Data Team • 11/02/2026
The vulnerability identified under issue identifier MSV-9748 and addressed by patch ALPS11411924 represents a critical memory management flaw within the Universal Serial Bus subsystem of the operating system. This specific defect is classified as a double free error, which occurs when an application or kernel component attempts to deallocate a block of memory that has already been freed. In the context of USB device handling, this typically arises from improper reference counting logic or race conditions during the teardown process of USB interfaces and endpoints. When a malicious actor interacts with a compromised or specially crafted USB peripheral, they can trigger specific sequences of events that cause the system to release the same memory address twice. This corruption disrupts the internal data structures used by the kernel for managing heap allocations, potentially allowing an attacker to overwrite adjacent memory regions with controlled values.
From a technical perspective, this flaw aligns closely with Common Weakness Enumeration identifier CWE-415, which describes double free vulnerabilities that lead to undefined behavior and potential code execution. The exploitation of this vulnerability does not require user interaction, meaning the attack vector is fully automated once physical access or proximity to an infected USB device is established. However, a significant constraint in the current threat model is the privilege level required for successful exploitation. As noted, the attacker must already possess System privileges. This implies that while the memory corruption itself can be triggered by lower-privileged processes or hardware interactions, achieving full control over the system likely requires an initial foothold at the highest administrative level. Consequently, this vulnerability serves primarily as a mechanism to maintain persistence or escalate privileges within environments where boundary controls have already been breached, rather than serving as a standalone entry point for unauthenticated remote code execution.
The operational impact of this flaw is severe in scenarios involving trusted but compromised systems. If an attacker has gained System-level access through other means, such as exploiting a separate vulnerability or leveraging stolen credentials, they can utilize this USB subsystem double free to further destabilize the kernel state. By corrupting memory structures like heap metadata or function pointers, the attacker may achieve arbitrary code execution within the kernel space. This effectively neutralizes many security mitigations that rely on user-mode isolation, as kernel-level compromise grants unrestricted access to all system resources, including sensitive data stored in protected areas of memory. The lack of required user interaction makes this particularly dangerous for automated systems or devices left unattended with USB ports accessible, although the high privilege requirement limits its utility against well-hardened endpoints where initial access is difficult to obtain.
To mitigate the risks associated with MSV-9748, organizations should prioritize the immediate application of patch ALPS11411924 across all affected systems. Beyond software updates, defensive strategies should focus on reducing the attack surface related to USB interfaces. This includes implementing strict device control policies that restrict the types of USB devices allowed to connect to corporate networks and endpoints. Utilizing hardware-based solutions such as USB data blockers or port disablement for unused ports can prevent physical access attacks entirely. Additionally, deploying endpoint detection and response tools capable of monitoring for anomalous memory allocation patterns may help detect exploitation attempts in real-time. Security teams should also review their privilege management policies to ensure that System-level accounts are not unnecessarily exposed to network-accessible services or user sessions, thereby raising the bar for any potential attacker seeking to leverage this vulnerability after gaining initial access.