CVE-2015-6016 in P-660HW-T1
Summary
by MITRE
ZyXEL P-660HW-T1 2 devices with ZyNOS firmware 3.40(AXH.0), PMG5318-B20A devices with firmware 1.00AANC0b5, and NBG-418N devices have a default password of 1234 for the admin account, which allows remote attackers to obtain administrative access via unspecified vectors.
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Analysis
by VulDB Data Team • 11/09/2024
The vulnerability identified as CVE-2015-6016 represents a critical authentication flaw affecting multiple ZyXEL networking devices including the P-660HW-T1, PMG5318-B20A, and NBG-418N models. This security weakness stems from the implementation of a hardcoded default password of "1234" for the administrative account within the ZyNOS firmware versions 3.40(AXH.0) and 1.00AANC0b5 respectively. The flaw creates a persistent backdoor that enables remote attackers to gain full administrative privileges without requiring any specialized tools or complex exploitation techniques.
The technical nature of this vulnerability aligns with CWE-798, which specifically addresses the use of hard-coded credentials in software applications. This particular implementation flaw allows attackers to bypass normal authentication mechanisms entirely since the default password remains unchanged across deployments. The unspecified vectors mentioned in the description suggest that the vulnerability can be exploited through various network access points including web interfaces, telnet, or other management protocols that are typically exposed to external networks. The weakness is particularly concerning because it exists at the firmware level, meaning that even if users attempt to change the password, the default credential remains accessible through alternative access methods.
The operational impact of this vulnerability extends beyond simple unauthorized access as it provides attackers with complete control over affected devices. Once administrative access is obtained, attackers can modify network configurations, install malicious firmware, redirect traffic, or establish persistent access points within the network. This vulnerability directly maps to several ATT&CK techniques including T1078 for valid accounts and T1046 for network service scanning, as attackers can leverage the default credential to gain access to network infrastructure. The remote exploit capability means that no physical access or local network presence is required, making the attack surface significantly larger than typical network security threats.
Organizations should immediately implement mitigations including changing default passwords on all affected devices, disabling unnecessary management services, and implementing network segmentation to isolate critical infrastructure. Network administrators should also consider deploying intrusion detection systems to monitor for unauthorized access attempts and conduct regular vulnerability assessments to identify similar hardcoded credentials across their network infrastructure. The vulnerability highlights the importance of proper credential management practices and the necessity of implementing strong authentication mechanisms from the initial device deployment rather than relying on default configurations that may remain unchanged for extended periods.