The SMTP service must not have the VRFY feature active.

From HP-UX 11.31 Security Technical Implementation Guide

Associated with IA controls: ECSC-1

Associated with: CCI-000366

SV-35083r1_rule The SMTP service must not have the VRFY feature active.

Vulnerability discussion

The VRFY (Verify) command allows an attacker to determine if an account exists on a system, providing significant assistance to a brute force attack on user accounts. VRFY may provide additional information about users on the system, such as the full names of account owners.

Check content

Fix text

If running Sendmail, add the line Opnovrfy to the Sendmail configuration file, usually located in /etc/mail/sendmail.cf. For other mail servers, contact the vendor for information on how to disable the verify command. Newer versions of Sendmail are available at http://www.sendmail.org or from ftp://ftp.cs.berkeley.edu/ucb/sendmail. Edit the /etc/mail/sendmail.cf file and add or edit (one of) the following line(s): O PrivacyOptions=novrfy O PrivacyOptions=goaway Then restart the Sendmail service.

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.