VULHUB ™

Cisco Secure Email Gateways, formerly known as Cisco Ironport Email Security Appliances, that are configured to detect malicious email attachments, can easily be circumvented. A remote attacker can leverage error tolerance and different MIME decoding capabilities of email clients, compared with the gateway, to evade detection of malicious payloads by anti-virus components on the gateway. This exploit was successfully tested with a zip file containing the Eicar test virus and Cisco Secure Email Gateways with AsyncOS 14.2.0-620, 14.0.0-698, and others. An affected Email Client was Mozilla Thunderbird 91.11.0 (64-bit).

Cisco Secure Email Gateways, formerly known as Cisco Ironport Email Security Appliances, that are configured to detect malicious email attachments, can easily be circumvented. A remote attacker can leverage error tolerance and different MIME decoding capabilities of email clients, compared with the gateway, to evade detection of malicious payloads by anti-virus components on the gateway. This exploit was successfully tested with a zip file containing the Eicar test virus and Cisco Secure Email Gateways with AsyncOS 14.2.0-620, 14.0.0-698, and others. An affected Email Client was Mozilla Thunderbird 91.11.0 (64-bit).