SMTP Binding Configuration Settings Bypassed

SUMMARY

Symantec responded to a potential vulnerability identified in the SMTP binding function of the entry-level Symantec Gateway Security appliances with the ISP load-balancing capabilities. In certain firmware versions, the SMTP (outbound email) traffic would be load-balanced regardless of the user-configured WAN binding selection. This could result in SMTP traffic intended only for a trusted network potentially being passed over an untrusted connection instead.

AFFECTED PRODUCTS

Affected Components

ISSUES

Details
Symantec was notified of this potential vulnerability in a Symantec Gateway Security 360 appliance configured to load-balance two ISPs with SMTP binding set for a single WAN. The SMTP binding configuration was not being implemented as selected causing SMTP traffic to be load-balanced through both WAN1 and WAN2. This could result in a potential vulnerability if a trusted network was selected for SMTP binding through one WAN and an untrusted network connected to the other WAN. SMTP traffic bound to the trusted network could potentially be passed over both the trusted and untrusted WANs (load-balanced).

The Common Vulnerabilities and Exposures (CVE) initiative has assigned CVE Candidate CAN-2005-0618 to this issue.

This issue is a candidate for inclusion in the CVE list (<http://cve.mitre.org>), which standardizes names for security problems.

MITIGATION

Symantec Response
Symantec confirmed the potential vulnerability and determined that the issue was also present in the Symantec Gateway Security 460, Symantec Firewall/VPN Appliance 200, and the legacy Nexland Pro800turbo models that also provide load-balancing capabilities.

Symantec has released the following firmware releases that address this issue:

• Build 1.68: Symantec Firewall/VPN Appliance models 200 and 200R
• Build 858: Symantec Gateway Security Appliance models 360 and 360R
• Build 1.6X: Nexland Pro800turbo

Symantec recommends customers using SMTP binding in load-balanced configurations apply the appropriate firmware for their affected product models/versions to remedy this issue.

Product specific firmware and hotfixes are available via the Symantec Enterprise Support site at <http://www.symantec.com/techsupp&gt;.

ACKNOWLEDGEMENTS

Symantec appreciates the actions of Arthur Hagen, Broomstick Net Services, in identifying this issue, notifying Symantec and providing extensive cooperation and coordination while Symantec resolved the issue.

REVISION

Revision History
3/2/2005 - Added CVE Candidate CAN-2005-0618