CVE-2018-15453

Technical Description

A vulnerability in the Secure/Multipurpose Internet Mail Extensions (S/MIME) Decryption and Verification or S/MIME Public Key Harvesting features of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause an affected device to corrupt system memory. A successful exploit could cause the filtering process to unexpectedly reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to improper input validation of S/MIME-signed emails. An attacker could exploit this vulnerability by sending a malicious S/MIME-signed email through a targeted device. If Decryption and Verification or Public Key Harvesting is configured, the filtering process could crash due to memory corruption and restart, resulting in a DoS condition. The software could then resume processing the same S/MIME-signed email, causing the filtering process to crash and restart again. A successful exploit could allow the attacker

Remediation

Check the references section for vendor advisories and patches from cisco. Update email_security_appliance_firmware to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References