CVE-2026-20506 in MT2718
Summary
by MITRE • 09/07/2026
In Audio HAL, there is a possible escalation of privilege due to use after 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: ALPS11191981; Issue ID: MSV-9126.
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Analysis
by VulDB Data Team • 09/07/2026
The vulnerability identified under issue identifier MSV-9126 and patch reference ALPS11191981 resides within the Audio Hardware Abstraction Layer, a critical component in Android-based operating systems that serves as an interface between higher-level audio frameworks and low-level hardware drivers. This specific flaw is classified as a use-after-free error, which represents a severe memory management defect where software continues to utilize a pointer after the memory it references has been reallocated or freed by the system. In the context of the Audio HAL, this typically occurs when an object representing an audio stream, device, or callback handler is destroyed and its memory returned to the heap allocator, but subsequent operations within the audio subsystem fail to nullify the reference or check for validity before attempting to access it. This creates a window where malicious code can manipulate the freed memory region to contain controlled data, thereby influencing the behavior of the program when that stale pointer is dereferenced again during normal audio processing tasks such as playback, recording, or system sound events.
From a technical perspective, use-after-free vulnerabilities are particularly dangerous because they allow an attacker to achieve arbitrary read and write capabilities within the process space where the vulnerability exists. Since the Audio HAL operates with high privileges in many Android configurations, successfully exploiting this flaw can lead to local privilege escalation. The description notes that exploitation requires the actor to already possess System-level permissions. This indicates that while the immediate impact is an elevation of rights beyond what was originally granted within a specific context or sandboxed environment, it does not represent a zero-click remote code execution from untrusted user space. Instead, it facilitates lateral movement or privilege escalation among system services and privileged applications that have been compromised or are running with elevated tokens. The absence of required user interaction means the attack vector is purely technical and can be executed automatically once the prerequisite System privileges are established, making it a significant risk for devices where attackers may already have footholds through other vulnerabilities or physical access scenarios.
The operational impact of this vulnerability extends beyond simple privilege escalation to include potential stability issues within the audio subsystem itself. Use-after-free conditions often lead to crashes, data corruption, or unpredictable behavior in media applications and system services that rely on consistent audio routing and processing. For enterprise environments or devices handling sensitive communications, such instability can disrupt critical operations. Furthermore, because this flaw exists at a foundational layer of the operating system architecture, it undermines the integrity of the security model by allowing processes with System privileges to bypass intended restrictions or access protected resources they should not be able to reach. This aligns closely with CWE-416, which defines use-after-free as an error where software uses memory after it has been freed, leading to undefined behavior and potential exploitation.
In terms of threat modeling and attack classification, this vulnerability maps to the ATT&CK technique T1055, specifically Process Injection or Memory Manipulation subcategories, depending on how the attacker leverages the arbitrary write capability derived from the use-after-free condition. It also relates to CWE-787, which covers out-of-bounds writes that can occur when manipulating freed memory structures. The mitigation strategy primarily involves applying the provided patch ALPS11191981, which likely includes code changes to ensure proper lifecycle management of audio objects, including nullifying pointers after deallocation and adding validation checks before dereferencing them. Developers should also implement robust static analysis tools and dynamic fuzzing techniques targeting the Audio HAL interface to detect similar memory safety issues early in the development cycle. For system administrators, ensuring that devices are updated with this patch is critical to maintaining the integrity of the privilege separation model within Android-based ecosystems.