CVE-2002-0949 in ADSL Router
Summary
by MITRE
Telindus 1100 series ADSL router allows remote attackers to gain privileges to the device via a certain packet to UDP port 9833, which generates a reply that includes the router s password and other sensitive information in cleartext.
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Analysis
by VulDB Data Team • 09/10/2025
The Telindus 1100 series ADSL router presents a critical privilege escalation vulnerability that enables remote attackers to obtain administrative credentials and sensitive system information through a specific UDP packet transmission to port 9833. This vulnerability represents a fundamental flaw in the router's authentication and information disclosure mechanisms, allowing unauthorized parties to bypass normal security controls and gain full administrative access to the device. The flaw exists within the router's network service implementation where a carefully crafted packet triggers a response containing cleartext passwords and other confidential data, effectively providing attackers with immediate administrative privileges.
This vulnerability directly maps to CWE-200, which describes information exposure through a poorly designed network service that reveals sensitive data in cleartext format. The technical implementation flaw lies in the router's failure to properly validate incoming UDP packets on port 9833 or to implement proper authentication mechanisms before responding with sensitive information. The service appears to be a diagnostic or management interface that responds to specific queries without adequate verification of the sender's identity or authorization level. The cleartext transmission of passwords and sensitive information violates fundamental security principles and creates an immediate risk for network administrators who may unknowingly rely on this vulnerable device for their network infrastructure.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over the router's configuration and network traffic management capabilities. Once compromised, an attacker can modify firewall rules, redirect network traffic, implement man-in-the-middle attacks, or establish persistent backdoors within the network. The cleartext exposure of passwords means that not only can attackers gain administrative access, but they can also potentially access other systems that may have been configured with the same credentials. This vulnerability affects network security posture at the gateway level, where the router serves as the primary defense mechanism between internal networks and external threats. The attack vector is particularly concerning because it requires no authentication from the attacker's perspective and can be executed remotely, making it an attractive target for automated exploitation tools.
Mitigation strategies for this vulnerability should include immediate network segmentation to isolate affected routers from critical network segments, implementation of network access control lists to block traffic to UDP port 9833, and deployment of intrusion detection systems to monitor for exploitation attempts. Organizations should also consider disabling unused network services and interfaces on the affected devices, implementing network monitoring to detect anomalous traffic patterns, and conducting comprehensive vulnerability assessments of their entire network infrastructure. The remediation process requires firmware updates from Telindus if available, or complete replacement of affected devices with versions that properly implement authentication and encryption mechanisms. Security controls should align with nist cybersecurity framework principles, particularly in ensuring that network devices properly implement authentication, access control, and information protection measures to prevent unauthorized access and data disclosure.