CVE-2025-27457 in MEAC300-FNADE4
Summary
by MITRE • 07/03/2025
All communication between the VNC server and client(s) is unencrypted. This allows an attacker to intercept the traffic and obtain sensitive data.
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Analysis
by VulDB Data Team • 02/06/2026
The vulnerability identified as CVE-2025-27457 represents a critical security flaw in Virtual Network Computing implementations where all communication between the VNC server and client components occurs without encryption. This fundamental weakness exposes the entire VNC ecosystem to man-in-the-middle attacks and passive network surveillance. The absence of encryption creates an environment where attackers can easily intercept and analyze network traffic flowing between VNC servers and their connected clients, potentially compromising the confidentiality of all transmitted data.
This vulnerability directly maps to CWE-319, which specifically addresses the exposure of sensitive information through improper encryption of network communications. The technical flaw stems from the VNC protocol implementation failing to establish secure communication channels, leaving authentication credentials, session data, and any information exchanged between server and client components vulnerable to interception. Network traffic analysis tools can readily capture and decode VNC communications, making this attack vector particularly attractive to threat actors seeking unauthorized access to systems.
The operational impact of this vulnerability extends far beyond simple credential theft, as it enables comprehensive session monitoring and potential system compromise. Attackers can observe user interactions, capture keystrokes, access clipboard contents, and potentially escalate privileges through session hijacking. The unencrypted nature of VNC communications means that even seemingly innocuous network traffic can reveal sensitive information about system configurations, user activities, and internal network structures. This vulnerability particularly affects environments where VNC is used for remote administration, technical support, or system monitoring without additional security layers.
Organizations utilizing VNC services must implement immediate mitigations to address this vulnerability, including mandatory encryption protocols such as TLS/SSL tunneling, VPN implementation for secure access, or deployment of VNC solutions with built-in encryption capabilities. The ATT&CK framework categorizes this vulnerability under T1046 network service scanning and T1566 credential access techniques, emphasizing the need for layered security approaches. Network segmentation, firewall rules restricting VNC access, and regular security audits of remote access implementations should be implemented as part of comprehensive defense strategies. Additionally, organizations should consider migrating to more secure remote desktop protocols such as RDP with strong encryption or SSH-based tunneling solutions that provide end-to-end protection for remote access communications.