CVE-2005-0328 in RT311
Summary
by MITRE
Zyxel P310, P314, P324 and Netgear RT311, RT314 running the latest firmware, allows remote attackers on the WAN to obtain the IP address of the LAN side interface by pinging a valid LAN IP address, which generates an ARP reply from the WAN address side that maps the LAN IP address to the WAN s MAC address.
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Analysis
by VulDB Data Team • 07/22/2017
This vulnerability affects ZyXel P310, P314, P324 and Netgear RT311, RT314 wireless routers running their latest firmware versions. The issue stems from improper network interface handling where the routers fail to properly isolate the WAN and LAN sides of their network configuration. When a remote attacker on the WAN side sends a ping request to a valid LAN IP address, the router's networking stack generates an ARP reply that reveals the LAN IP address mapping to the WAN interface's MAC address. This behavior violates fundamental network security principles and exposes internal network topology information to external adversaries.
The technical flaw resides in the router's ARP response handling mechanism which does not properly validate the source of ARP requests or enforce proper network boundary enforcement between the WAN and LAN interfaces. According to CWE-200, this represents an information exposure vulnerability where sensitive network information is inadvertently disclosed to unauthorized parties. The vulnerability demonstrates a classic case of insufficient network segmentation where the device fails to maintain proper isolation between different network zones, allowing cross-zone information leakage.
The operational impact of this vulnerability is significant as it provides remote attackers with valuable network topology information that can be used for further reconnaissance and attack planning. An attacker can discover valid LAN IP addresses and potentially map internal network structures without requiring any authentication or privileged access. This information leakage enables more sophisticated attacks such as targeted ARP spoofing, internal network scanning, or social engineering campaigns that leverage the discovered network topology. The vulnerability specifically aligns with ATT&CK technique T1046 which involves network service scanning, and T1082 which involves system information discovery.
Mitigation strategies should focus on implementing proper network segmentation controls and disabling unnecessary services that could expose internal network information. Network administrators should ensure that routers are configured with appropriate firewall rules that prevent ARP responses from being generated for internal network addresses when accessed from external interfaces. The recommended approach includes enabling strict ARP filtering, implementing proper routing table configurations, and ensuring that the device's firmware is updated with security patches that address this specific information disclosure vulnerability. Additionally, network monitoring should be implemented to detect unusual ARP activity patterns that might indicate exploitation attempts.