CVE-2003-0419 in Barricade Wireless Cable Dsl Broadband Router
Summary
by MITRE
SMC Networks Barricade Wireless Cable/DSL Broadband Router SMC7004VWBR allows remote attackers to cause a denial of service via certain packets to PPTP port 1723 on the internal interface.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/03/2019
The SMC Networks Barricade Wireless CableDSL Broadband Router model SMC7004VWBR presents a significant denial of service vulnerability that affects the Point-to-Point Tunneling Protocol implementation within the device. This vulnerability specifically targets the internal interface of the router where PPTP port 1723 is accessible, creating an attack surface that remote adversaries can exploit to disrupt normal network operations. The flaw exists in the router's handling of certain packet structures destined for the PPTP control channel, which operates on TCP port 1723 as defined in the PPTP specification. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-129 Input Validation, as the device fails to properly validate incoming packets before processing them through the PPTP protocol stack. The attack vector allows remote exploitation since the vulnerable service is accessible from external networks, though the attack must target the internal interface, indicating a potential misconfiguration or insufficient network segmentation.
The technical implementation of this vulnerability stems from insufficient input validation and error handling within the router's PPTP processing module. When malformed or specially crafted packets are sent to the PPTP port 1723 on the internal interface, the router's protocol implementation fails to properly sanitize or reject these packets, leading to a system crash or complete service disruption. This behavior aligns with the ATT&CK framework's T1499 technique for Network Denial of Service, where adversaries leverage protocol-specific weaknesses to exhaust system resources or trigger critical failures. The vulnerability essentially causes the router to enter an unstable state where it cannot properly handle subsequent network traffic, effectively creating a denial of service condition that impacts all connected devices. The impact extends beyond simple connectivity disruption as the router may require manual intervention or power cycling to restore normal operations.
The operational impact of this vulnerability creates significant risks for network availability and business continuity, particularly in environments where the router serves as a critical network gateway. Organizations relying on this device for internet connectivity face potential downtime that could affect multiple users and applications simultaneously. The vulnerability's exposure through the internal interface suggests that network segmentation may be inadequate, potentially allowing attackers to move laterally within the network or exploit other connected devices. Security professionals should note that this vulnerability demonstrates the importance of proper network architecture and the principle of least privilege in device configuration. The affected router model represents a legacy device that lacks modern security hardening features, making it particularly susceptible to protocol-based attacks. Organizations with multiple instances of this router model should prioritize immediate remediation through firmware updates or network segmentation to prevent exploitation.
Mitigation strategies for this vulnerability should focus on both immediate defensive measures and long-term architectural improvements. Network administrators should implement firewall rules to block access to PPTP port 1723 from external networks when PPTP is not actively required, though this may not fully address the internal interface exposure. The most effective immediate solution involves applying vendor-provided firmware updates that contain patches for the PPTP processing module. Additionally, implementing network monitoring to detect unusual traffic patterns on port 1723 can help identify potential exploitation attempts. Organizations should also consider disabling PPTP services entirely if they are not essential for business operations, as recommended by the NIST Cybersecurity Framework. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date firmware across all network infrastructure components and the necessity of conducting regular security assessments to identify and remediate similar weaknesses in legacy devices.