CVE-2026-108071 in Remote Access
Summary
by MITRE • 10/14/2026
Incorrect authentication vulnerability in the TSplus Remote Access multi-factor authentication (MFA) mechanism. A remote attacker authenticated with valid first-factor credentials could bypass the second-factor verification because the authentication flow does not correctly apply the MFA validation result, allowing the attacker to complete the login without a valid second-factor token and gain access to protected applications and resources.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified in TSplus Remote Access represents a critical failure in the implementation of multi-factor authentication protocols, specifically within the mechanism designed to enforce secondary verification steps. Multi-factor authentication is intended to provide layered security by requiring users to present two or more independent credentials to gain access to an application or system. In this specific instance, the flaw lies not in the strength of the individual factors themselves but rather in the logical flow that processes them. The remote attacker was able to authenticate using valid first-factor credentials, which typically consist of something the user knows, such as a username and password. However, the subsequent step requiring the second factor, often something the user has like a hardware token or time-based one-time code, was effectively bypassed due to an error in how the authentication state is managed and validated by the server-side logic.
From a technical perspective, this issue stems from improper validation of the MFA result during the login sequence. When a user initiates a connection, the system should verify that both factors have been successfully authenticated before granting session access. In this case, the application fails to correctly apply or check the outcome of the second-factor verification process. This logical error allows an attacker who possesses legitimate first-factor credentials to skip the requirement for the second factor entirely. The authentication flow proceeds as if the secondary validation had succeeded, thereby completing the login process without any evidence that the user possessed the required physical token or generated code. This type of flaw is particularly dangerous because it undermines the fundamental premise of MFA, which relies on the assumption that compromising one credential does not grant full access to an account.
The operational impact of this vulnerability is severe, as it effectively nullifies the security benefits provided by multi-factor authentication for any user whose first factor has been compromised. If an attacker obtains valid credentials through phishing, brute force attacks, or data breaches from other services, they can immediately gain unauthorized access to protected applications and sensitive resources hosted on the TSplus Remote Access server. This bypass allows for unrestricted lateral movement within the network once inside, potentially leading to data exfiltration, system manipulation, or further exploitation of connected systems. The ability to authenticate without the second factor means that organizations relying solely on this MFA implementation cannot trust their authentication logs as indicators of legitimate user activity, complicating incident response and forensic analysis efforts.
This vulnerability aligns with CWE-287, which describes Improper Authentication, specifically relating to failures in verifying multiple factors or incorrectly handling authentication states. It also maps to MITRE ATT&CK technique T1078, Valid Accounts, as the attacker leverages legitimate credentials but exploits a flaw in the verification process to gain unauthorized access. To mitigate this risk, immediate action is required from system administrators and developers responsible for maintaining TSplus Remote Access environments. The primary mitigation involves applying any available patches or updates released by the vendor that address the logical error in the MFA validation flow. Until such fixes are applied, organizations should consider implementing compensating controls such as network-level access restrictions using firewalls to limit exposure of the remote access service to trusted IP addresses only. Additionally, enforcing strict password policies and monitoring for anomalous login patterns can help detect potential exploitation attempts where valid credentials are used in unusual contexts or from unexpected locations.