CVE-2000-0738: WebShield SMTP 4.5 allows remote attackers to cause a denial of service by sending e-mail with a From: addr...

Security readout for executives and security teams

A flaw in WebShield SMTP 4.5, an older email gateway, lets an outsider send a message with a malformed sender address that ends in a period. The product mishandles that address and starts endlessly mailing copies to itself. The result is a denial of service that ties up the mail gateway and can delay or block legitimate email until the queue is cleared. Exposure is limited to organizations still running WebShield SMTP 4.5 (a legacy McAfee/Network Associates product) as an internet-facing mail gateway. Given the product's age (2000-era) and the vendor's subsequent product transitions, active production deployments in 2026 should be rare. Any remaining instance exposed to inbound SMTP would be reachable by any remote sender. Low priority for most organizations. Only material if a legacy WebShield SMTP 4.5 gateway is still in production; in that case, plan a scheduled replacement rather than an emergency response. Availability of email could be disrupted but no data confidentiality or integrity impact is indicated. Mitigation focus: Retire or replace WebShield SMTP 4.5; it is a legacy product with no cited fix.; Check current vendor (Trellix/McAfee successor) guidance for any supported upgrade path.; Route inbound SMTP through a modern, maintained mail gateway with loop protection..

Prepared

Jul 12, 2026, 00:03 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.