CVE-2004-2771: Bsd Mailx Project Bsd Mailx

High severity, CVSS 7.5. EPSS: 6.9% chance of exploitation in the next 30 days.

The expand function in fio.c in Heirloom mailx 12.5 and earlier and BSD mailx 8.1.2 and earlier allows remote attackers to execute arbitrary commands via shell metacharacters in an email address.

Affected products

• Bsd Mailx Project Bsd Mailx: up to and including 8.1.2
• Heirloom Mailx: up to and including 12.5
• Oracle Linux: version 6 only; version 7 only
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only

Published 2014-12-24. Last modified 2026-09-23.