CVE-2008-1522 in ZyNOS
Summary
by MITRE
ZyXEL Prestige routers, including P-660 and P-661 models with firmware 3.40(AGD.2) through 3.40(AHQ.3), have (1) "user" as their default password for the "user" account and (2) "1234" as their default password for the "admin" account, which makes it easier for remote attackers to obtain access.
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Analysis
by VulDB Data Team • 09/20/2018
The vulnerability identified in CVE-2008-1522 affects ZyXEL Prestige routers, specifically the P-660 and P-661 models, which are widely deployed in residential and small office environments. These routers operate with firmware versions ranging from 3.40(AGD.2) through 3.40(AHQ.3), creating a significant security risk due to their weak default authentication credentials. The flaw represents a critical configuration issue that undermines the fundamental security posture of these network devices, as it provides attackers with readily available access credentials that require no additional exploitation techniques to compromise the system.
The technical implementation of this vulnerability stems from the router's default configuration where the user account is assigned the password "user" and the administrative account uses the password "1234". This configuration violates fundamental security principles outlined in the OWASP Top Ten and NIST cybersecurity guidelines, as it creates a predictable and easily guessable authentication mechanism. The vulnerability specifically manifests as a weak credential flaw, which aligns with CWE-798, representing the use of hard-coded credentials that should never be present in production systems. Attackers can exploit this weakness remotely without requiring any specialized tools or complex techniques, as the default passwords are well-documented and readily accessible through various online resources.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as compromised routers can serve as entry points for broader network infiltration. When an attacker gains access to these devices, they can manipulate network configurations, redirect traffic, intercept communications, and potentially establish persistent backdoors within the network infrastructure. The remote accessibility of this vulnerability means that attackers do not need physical access to the device, making it particularly dangerous for organizations that rely on default configurations. This weakness can facilitate various attack vectors including man-in-the-middle attacks, DNS hijacking, and network reconnaissance activities, as outlined in the MITRE ATT&CK framework under the T1071.004 and T1046 categories.
Mitigation strategies for this vulnerability must focus on immediate credential changes and ongoing security monitoring. Network administrators should immediately update all default passwords to strong, unique credentials that meet complexity requirements, typically defined by NIST SP 800-63B standards. The implementation of automated patch management systems can help ensure that firmware updates are deployed promptly, as newer firmware versions typically address this specific weakness by removing or changing default credentials. Network segmentation and firewall rules should be implemented to limit access to router management interfaces, while logging mechanisms should be configured to monitor for unauthorized access attempts. Regular security audits and vulnerability assessments should be conducted to identify similar weak configurations across the entire network infrastructure, as this vulnerability represents a common pattern that may exist in other network devices within the same environment.