CVE-2003-1177: Atrium Software Mercur Mailserver

High severity, CVSS 7.5. EPSS: 12.9% chance of exploitation in the next 30 days.

Buffer overflow in the base64 decoder in MERCUR Mailserver 4.2 before SP3a allows remote attackers to cause a denial of service and possibly execute arbitrary code via a long (1) AUTH command to the POP3 server or (2) AUTHENTICATE command to the IMAP server.

Affected products

• Atrium Software Mercur Mailserver: version 3.3 only; version 3.3_sp1 only; version 3.3_sp2 only; version 4.1 only; version 4.1_sp1 only; version 4.2 only; …

Published 2003-12-31. Last modified 2026-06-16.