CVE-2017-6671: A vulnerability in the email message scanning of Cisco AsyncOS Software for Cisco Email Security Appliance...

Security readout for executives and security teams

This flaw could let a remote, unauthenticated sender get email past configured Cisco ESA scanning filters, including attachment filters. For organizations relying on ESA to block risky attachments or policy-violating mail, the impact is reduced email-gateway enforcement rather than direct appliance takeover based on the provided sources. Exposure is limited to Cisco Email Security Appliance deployments running the listed affected AsyncOS releases. Risk is highest where ESA filtering is a primary control for attachments, content policy, or mail hygiene enforcement. Prioritize remediation where ESA is business-critical for blocking risky attachments or enforcing compliance policy. The urgency is meaningful, but the provided evidence does not support treating this as an actively exploited emergency. Mitigation focus: Confirm all Cisco ESA appliances and AsyncOS versions in inventory.; Upgrade affected releases to Cisco-listed fixed releases 10.0.2-020 or 9.8.1-015.; Review Cisco advisory cisco-sa-20170607-esa1 and CSCvd34632 for vendor guidance..

Prepared

Jun 13, 2026, 04:43 UTC (UTC+00:00)

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