CVE-2026-20484 in MT6739
Summary
by MITRE • 08/03/2026
In TFA, there is a possible information disclosure due to a missing permission check. This could lead to local information disclosure if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11053160; Issue ID: MSV-8004.
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Analysis
by VulDB Data Team • 08/03/2026
This vulnerability represents a critical information disclosure flaw within the Trusted Firmware-A (TFA) framework that stems from an inadequate permission validation mechanism. The issue manifests as a missing access control check that allows unauthorized data exposure when specific system conditions are met. The vulnerability is particularly concerning because it operates without requiring any user interaction, making it highly exploitable in scenarios where an attacker has already achieved System privilege level access. This characteristic places the vulnerability squarely within the domain of privilege escalation and information disclosure attacks that can be leveraged to extract sensitive data from protected system components.
The technical implementation flaw resides in the TFA's permission checking mechanisms which fail to properly validate access rights before exposing sensitive information. When a malicious actor possesses System privileges, they can bypass normal security boundaries and access data that should remain protected. This missing permission check creates an information disclosure channel that operates at the firmware level, potentially exposing system configuration details, cryptographic keys, or other sensitive operational parameters. The vulnerability's classification aligns with CWE-284 which addresses improper access control issues, and it represents a significant weakness in the firmware security architecture that could enable broader compromise scenarios.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with valuable intelligence for further exploitation attempts. Once sensitive data is exposed through this flaw, adversaries can use the gathered information to craft more sophisticated attacks against other system components or to bypass additional security controls. The lack of user interaction requirement means that once an attacker achieves System privilege level access, they can automatically exploit this vulnerability without additional engagement steps. This characteristic makes the vulnerability particularly dangerous in persistent threat scenarios where attackers maintain long-term access to compromised systems.
Security mitigations for this vulnerability should focus on implementing comprehensive permission validation checks throughout the TFA framework, ensuring that all data access operations properly verify authorization levels before returning sensitive information. The patch ALPS11053160 specifically addresses this issue by restoring proper access control mechanisms within the firmware components. Organizations should also implement continuous monitoring of system privileges and access patterns to detect potential exploitation attempts. From an ATT&CK perspective, this vulnerability maps to techniques involving privilege escalation and credential access, making it particularly relevant for defensive security operations that focus on protecting system-level access controls and maintaining integrity of firmware components.