The SMTP service SMTP greeting must not provide version information.

From VMware vRealize Automation 7.x SLES Security Technical Implementation Guide

Associated with: CCI-000382

SV-100315r1_rule The SMTP service SMTP greeting must not provide version information.

Vulnerability discussion

The version of the SMTP service can be used by attackers to plan an attack based on vulnerabilities present in the specific version.

Check content

To check for the sendmail version being displayed in the greeting: # more /etc/sendmail.cf | grep SmtpGreetingMessage If it returns the following: O SmtpGreetingMessage=$j Sendmail $v/$Z; $b Then sendmail is providing version information, and this is a finding.

Fix text

Change the "O SmtpGreetingMessage" line in the /etc/sendmail.cf file to: O SmtpGreetingMessage= Mail Server Ready ; $b

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.