The SMTP services SMTP greeting must not provide version information.

From VMware vRealize Operations Manager 6.x SLES Security Technical Implementation Guide

Associated with: CCI-000382

SV-99197r1_rule The SMTP services 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: O SmtpGreetingMessage=$j Sendmail $v/$Z; $b Then sendmail is providing version information, this is a finding.

Fix text

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

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