CVE-2006-4765 in DG834GT
Summary
by MITRE
NETGEAR DG834GT Wireless ADSL router running firmware 1.01.28 allows attackers to cause a denial of service (device hang) via a long string in the username field in the login window.
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Analysis
by VulDB Data Team • 08/04/2018
The CVE-2006-4765 vulnerability affects NETGEAR DG834GT Wireless ADSL routers with firmware version 1.01.28, representing a classic buffer overflow condition that manifests as a denial of service attack. This vulnerability resides in the router's web-based management interface where the authentication mechanism fails to properly validate input length in the username field. The flaw enables malicious actors to exploit the device's insufficient input sanitization by submitting an excessively long string in the username parameter during login attempts. This particular vulnerability demonstrates how embedded network devices often lack proper bounds checking mechanisms that are standard in modern software development practices.
The technical implementation of this vulnerability stems from inadequate input validation within the router's authentication subsystem, specifically targeting the username field processing logic. When the router receives a login request containing an overly long string in the username field, the device's memory management fails to handle the excessive input gracefully, leading to system instability and eventual device hang or complete system freeze. This behavior aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a fundamental flaw in input validation and memory management practices within embedded systems. The vulnerability operates at the application layer of the network stack, making it accessible through standard web browser exploitation techniques without requiring specialized tools or deep system knowledge.
The operational impact of CVE-2006-4765 extends beyond simple service disruption to potentially compromise network availability for all connected devices. When successfully exploited, the denial of service condition renders the router completely inaccessible to legitimate users, effectively cutting off network connectivity for the entire local area network. This attack vector represents a significant concern for network administrators who rely on these devices for critical infrastructure connectivity, as the vulnerability can be exploited remotely without authentication requirements. The impact is particularly severe given that many organizations deploy these devices in mission-critical environments where network downtime directly translates to business disruption and potential financial losses.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening measures. The most effective immediate solution involves firmware updates from NETGEAR that implement proper input validation and bounds checking mechanisms for all authentication fields. Network administrators should also implement network segmentation and access control measures to limit exposure to this vulnerability, including restricting web management access to trusted networks only. Additionally, implementing intrusion detection systems that monitor for unusual login patterns and implementing regular security audits of network infrastructure can help identify potential exploitation attempts. This vulnerability exemplifies the importance of applying the principle of least privilege and demonstrates how seemingly minor input validation flaws can create significant security risks in network infrastructure devices. Organizations should also consider implementing network monitoring solutions that can detect device hang conditions and automatically trigger alerts when such anomalies occur, providing early warning of potential exploitation attempts. The vulnerability serves as a reminder of the critical need for regular firmware updates and proper security testing of embedded network devices before deployment in production environments.