CVE-2002-0602 in Lite+ Firewall
Summary
by MITRE
Snapgear Lite+ firewall 1.5.4 and 1.5.3 allows remote attackers to cause a denial of service (crash) via a large number of connections to (1) the HTTP web management port, or (2) the PPTP port.
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Analysis
by VulDB Data Team • 06/27/2021
The vulnerability identified as CVE-2002-0602 affects Snapgear Lite+ firewall versions 1.5.4 and 1.5.3, presenting a significant denial of service risk that can be exploited remotely by attackers. This weakness specifically targets two critical service ports of the firewall system, making it particularly dangerous for network security infrastructure. The vulnerability stems from inadequate input validation and connection handling mechanisms within the firewall's network service implementations, which fail to properly manage excessive connection requests.
The technical flaw manifests when attackers flood the targeted ports with an excessive number of simultaneous connections, causing the firewall to crash and become unavailable. This occurs because the system lacks proper connection rate limiting, connection queue management, and resource allocation controls. When the connection buffers overflow or system resources are exhausted, the firewall service becomes unresponsive, leading to complete service disruption. The vulnerability affects both the HTTP web management interface and the PPTP (Point-to-Point Tunneling Protocol) port, which are commonly used administrative and VPN access points respectively, making the attack surface particularly broad.
From an operational impact perspective, this vulnerability represents a critical threat to network availability and business continuity. Organizations relying on Snapgear Lite+ firewalls for network protection face potential service outages that could last from minutes to hours depending on the recovery process. The remote exploitation capability means attackers can initiate attacks from anywhere on the internet without requiring physical access or local network presence, significantly increasing the attack surface and reducing the time available for defensive response. Network administrators may experience complete loss of management capabilities during an attack, complicating incident response and recovery efforts.
The vulnerability aligns with CWE-400, which describes "Uncontrolled Resource Consumption" as a common weakness pattern, and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for "Endpoint Denial of Service." Organizations should implement immediate mitigations including connection rate limiting, firewall rules to restrict access to management ports, and network segmentation to isolate critical systems. Regular monitoring of connection counts and implementing automatic failover mechanisms can help detect and respond to such attacks. Additionally, upgrading to patched versions of Snapgear Lite+ firmware represents the most effective long-term solution, while network intrusion detection systems should be configured to alert on unusual connection patterns and high-volume port scanning activities. The vulnerability highlights the importance of proper resource management and input validation in network security appliances, particularly those handling administrative interfaces that are frequently targeted by attackers seeking to disrupt services.