CVE-2025-46176 in DIR-605L
Summary
by MITRE • 05/23/2025
Hardcoded credentials in the Telnet service in D-Link DIR-605L v2.13B01 and DIR-816L v2.06B01 allow attackers to remotely execute arbitrary commands via firmware analysis.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/23/2025
The vulnerability identified as CVE-2025-46176 represents a critical security flaw in the Telnet service implementation of D-Link DIR-605L v2.13B01 and DIR-816L v2.06B01 wireless routers. This issue stems from the presence of hardcoded credentials within the firmware, creating a persistent backdoor that remains accessible regardless of network configuration or user authentication attempts. The flaw specifically affects the Telnet service which is typically disabled by default on most networking equipment but can be enabled through various administrative interfaces or firmware modifications. Attackers exploiting this vulnerability can gain unauthorized access to the affected devices and execute arbitrary commands with elevated privileges, effectively compromising the entire network infrastructure.
The technical root cause of this vulnerability aligns with CWE-798, which addresses the use of hard-coded credentials in software applications. The implementation flaw occurs during the firmware development phase where developers embedded default login credentials directly into the router's codebase rather than implementing dynamic authentication mechanisms or secure credential management systems. This hardcoded approach eliminates the possibility of users changing default passwords or implementing proper access controls, making the vulnerability particularly dangerous as it persists across device reboots and firmware updates. The Telnet service in these specific D-Link models appears to utilize default credentials that remain unchanged throughout the device lifecycle, creating an inherent security weakness that directly violates industry best practices for network device security.
From an operational perspective, this vulnerability presents significant risk to organizations and individuals who rely on these specific router models for network connectivity. The remote execution capability allows attackers to perform a wide range of malicious activities including but not limited to network reconnaissance, data exfiltration, lateral movement within the network, and establishing persistent access points. The ability to execute arbitrary commands means that threat actors can modify router configurations, redirect network traffic, install malware, or create covert communication channels. This vulnerability particularly impacts enterprise environments where these routers may be used in branch offices or remote locations where physical access is limited, making the remote exploitation capability even more concerning. The nature of the flaw also suggests that attackers can potentially discover and exploit this vulnerability without requiring any specialized knowledge of the specific device model beyond basic network reconnaissance.
The attack surface for this vulnerability extends beyond simple unauthorized access to include broader network compromise scenarios. According to ATT&CK framework, this vulnerability maps to multiple techniques including T1078 for valid accounts and T1566 for phishing, as attackers can leverage the hardcoded credentials to establish persistence and laterally move within networks. Network defenders should consider this vulnerability as a potential entry point for advanced persistent threats, particularly given that many organizations fail to properly monitor or secure their network infrastructure devices. The firmware analysis approach mentioned in the vulnerability description indicates that attackers can reverse engineer the device firmware to discover the hardcoded credentials, making this vulnerability particularly dangerous as it can be discovered and exploited by both skilled and less sophisticated threat actors. Organizations using these specific router models should immediately implement network segmentation, monitor for unauthorized Telnet connections, and consider deploying network intrusion detection systems to identify potential exploitation attempts.
Recommended mitigations for this vulnerability include immediate firmware updates from D-Link to address the hardcoded credential issue, disabling Telnet services on affected devices, and implementing network access controls to prevent unauthorized access to administrative interfaces. Network administrators should also conduct thorough vulnerability assessments of their entire network infrastructure to identify similar hardcoded credential issues in other network devices. The implementation of secure remote access protocols such as SSH instead of Telnet, along with proper credential management policies, should be enforced across all network equipment. Additionally, organizations should consider deploying network monitoring solutions that can detect unusual Telnet connection patterns or unauthorized administrative access attempts, as these activities would typically be flagged by security information and event management systems. Regular firmware audits and security assessments should become standard practice to prevent similar vulnerabilities from being introduced in future device deployments.