A vulnerability exists in multiple Symantec security appliances that could allow a remote attacker to bypass the firewall using a source port of 53/udp.
Symantec's Firewall/VPN appliances and Gateway Security models include a number of services such as tftpd, snmpd, and isakmp. Access to these services from the WAN interface can be restricted through the use of the packet filtering feature of the device. The packet filtering feature contains a vulnerability that could allow a remote attacker to successfully connect to one of these services by specifying a source port of 53/udp.
A remote, unauthenticated attacker may be able to establish connections to services in violation of security policies. As a result, an attacker could send packets to these services that are configured to be unreachable from the WAN interface. An attacker could also leverage this flaw to exploit a vulnerability in one of these services. For instance, there is a vulnerability in the Firewall/VPN and Gateway Security appliances that allows a remote attacker to read and modify any SNMP object present on an affected device (VU#173910).
This vulnerability was reported by Symantec. Symantec credits Mike Sues and the Rigel Kent Security & Advisory Services for discovering the vulnerability.
This document was written by Damon Morda.
|Date First Published:||2004-10-20|
|Date Last Updated:||2004-10-20 14:36 UTC|