More on DNS Security Issue Management – Know & Control DNS + SOHO Issues

Just added this to Revision 2 of the whitepaper:

Attack Vector Management

Part of mitigating the risk of this security issue is also managing the availability of the attack vector. In this case, it is essential that security teams understand how DNS resolution operates in their environment. DNS resolution must be controlled to the greatest extent possible. That means that all servers and workstations MUST be configured to use a set of known, trusted and approved DNS servers whenever possible. In addition, proper egress filtering should be implemented to prevent external DNS resolution and contact with port 53 on unknown systems. Without control over desktop and server DNS use, the attack vector available for exploitation becomes unmanageably large. Upper management must support the adoption of these controls in order to prevent compromise as this and other DNS vulnerabilities evolve.

Home User and Small Office Vulnerability

Home users and small offices (or enclaves within larger organizations) should pay careful attention to how their DNS resolution takes place. Many home and small business firewall devices such as Linksys, D-Link, Netgear, etc. are likely to be vulnerable to these attacks and are quite UNLIKELY to be patched to current firmware levels. Efforts must be made to educate home and small office users about this issue and to update all of these devices as the patches and upgrades to their firmware becomes available.

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