CVE-2026-20599 in MT2716
Summary
by MITRE • 11/02/2026
In Modem, there is a possible escalation of privilege due to a missing permission check. 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: MOLY01790985; Issue ID: MSV-8148.
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Analysis
by VulDB Data Team • 11/02/2026
The vulnerability identified under CVE identifier associated with Modem firmware, specifically linked to patch MOLY01790985 and issue MSV-8148, represents a critical security flaw rooted in insufficient access control mechanisms within the modem subsystem. This defect allows for an escalation of privilege when specific conditions are met, fundamentally undermining the integrity of the device's operating environment. The core technical nature of this vulnerability is classified as CWE-269, which denotes Improper Privilege Management or Missing Permission Checks. In typical system architectures, particularly those involving cellular modems and baseband processors, strict separation of privileges exists between user-space applications and kernel-level or firmware-level components to prevent unauthorized modifications to critical system resources. The absence of a mandatory permission check in this specific context means that the modem software fails to verify whether an executing entity possesses the requisite authority before allowing actions that affect higher-privilege states or sensitive hardware registers.
The operational impact of this flaw is severe, as it facilitates local privilege escalation from lower-level contexts up to System privileges. While the description notes that exploitation requires a malicious actor who has already obtained System privilege, this phrasing often indicates a nuanced attack vector where an attacker may leverage other vulnerabilities or misconfigurations to gain initial foothold at a reduced privilege level and then exploit this specific modem flaw to achieve full administrative control over the device's communication stack. Alternatively, in some firmware architectures, "System" might refer to a high-level service account rather than root/kernel access, meaning that gaining System privileges could allow an attacker to intercept network traffic, modify radio parameters, or disable security features entirely. The fact that user interaction is not required for exploitation significantly increases the risk profile, as this vulnerability can be triggered remotely via crafted data packets or through automated processes running on compromised endpoints connected to the device. This aligns with ATT&CK technique T1068 Exploitation for Privilege Escalation, where adversaries leverage software vulnerabilities to gain higher-level access without direct user engagement.
From a defensive perspective, mitigating this vulnerability requires both immediate patching and long-term architectural improvements. The primary remediation is the application of the provided patch MOLY01790985, which presumably implements rigorous validation checks before executing privileged operations within the modem firmware. Beyond applying patches, organizations should enforce strict input validation on all data interfaces interacting with the modem subsystem to ensure that only authorized commands are processed. Additionally, implementing defense-in-depth strategies such as memory protection mechanisms and sandboxing for modem processes can limit the blast radius if a similar flaw is discovered in the future. Regular security audits focusing on access control lists and permission models within embedded systems are essential to prevent recurrence of CWE-269 type issues. Maintaining up-to-date firmware versions remains the most effective countermeasure against such privilege escalation vectors, ensuring that known gaps in authentication and authorization logic are closed before they can be leveraged by threat actors for persistent access or data exfiltration.