Bsd · Bsd Mailx · CVE-2004-2771
**Name of the Vulnerable Software and Affected Versions**
Heirloom mailx versions 12.5 and earlier
BSD mailx versions 8.1.2 and earlier
**Description**
The issue allows remote attackers to execute arbitrary commands via shell metacharacters in an email address, specifically through the expand function in fio.c.
**Recommendations**
For Heirloom mailx versions 12.5 and earlier, update to a version later than 12.5 to resolve the issue.
For BSD mailx versions 8.1.2 and earlier, update to a version later than 8.1.2 to resolve the issue.
As a temporary workaround, consider restricting the use of email addresses that may contain shell metacharacters until a patch is available.