The sendmail server must have the debug feature disabled on AIX systems.

Debug mode is a feature present in older versions of Sendmail which, if not disabled, may allow an attacker to gain access to a system through the Sendmail service.

Check the version of "sendmail" installed on the system using: # echo \$Z | /usr/sbin/sendmail -bt -d0

The above command should yield the following output: Version AIX7.2/8.14.4 Compiled with: DNSMAP LDAPMAP LDAP_REFERRALS LOG MAP_REGEX MATCHGECOS MILTER MIME7TO8 MIME8TO7 NAMED_BIND NDBM NETINET NETINET6 NETUNIX NEWDB NIS NISPLUS PIPELINING SCANF USERDB USE_LDAP_INIT USE_TTYPATH XDEBUG

If the "sendmail" reported version is less than "8.6", this is a finding.

Obtain and install a more recent version of "Sendmail", which does not implement the DEBUG feature.