CVE-2025-51451 in EX1200T
Summary
by MITRE • 08/13/2025
In TOTOLINK EX1200T firmware 4.1.2cu.5215, an attacker can bypass login by sending a specific request through formLoginAuth.htm.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/14/2025
The vulnerability identified as CVE-2025-51451 affects the TOTOLINK EX1200T wireless router running firmware version 4.1.2cu.5215, representing a critical authentication bypass flaw that undermines the device's security posture. This issue resides within the web-based management interface authentication mechanism, specifically targeting the formLoginAuth.htm component that handles user login requests. The vulnerability stems from inadequate input validation and authentication flow control within the firmware's web server implementation, allowing unauthorized access to the administrative interface without proper credentials.
The technical exploitation of this vulnerability occurs through a crafted HTTP request sent to the formLoginAuth.htm endpoint, which bypasses the normal authentication sequence by manipulating the login form parameters or by exploiting a logic flaw in the authentication validation process. This flaw enables attackers to gain administrative access to the device without knowledge of valid login credentials, effectively compromising the entire network infrastructure controlled by the router. The vulnerability can be classified under CWE-287 - Improper Authentication, which specifically addresses situations where authentication mechanisms fail to properly verify user identity. From an operational perspective, this authentication bypass represents a severe risk as it allows attackers to modify network configurations, install malicious firmware, or establish persistent access points within the network.
The impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with complete administrative control over the router's configuration and network settings. Network administrators lose control over critical security policies, firewall rules, and wireless network parameters that are essential for maintaining network security. The vulnerability also aligns with ATT&CK technique T1078 - Valid Accounts, as it allows adversaries to achieve persistence and maintain access without requiring legitimate credentials. Attackers could potentially use this access to create backdoor accounts, modify DNS settings to redirect traffic, or disable security features such as firewall rules and intrusion detection systems.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from TOTOLINK to address the authentication bypass flaw. Network administrators should also implement network segmentation to limit the impact of compromised devices, deploy intrusion detection systems to monitor for suspicious login attempts, and consider disabling remote administrative access where possible. The vulnerability highlights the importance of secure authentication implementation and proper input validation in embedded systems, as outlined in industry best practices for firmware security. Organizations should also conduct regular security assessments of network infrastructure devices to identify similar authentication bypass vulnerabilities that could compromise their overall security posture.