Rule ID
SV-239541r662074_rule
Version
V2R2
CCIs
CCI-000382
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.
Use the following command to check if VRFY is disabled: # grep -v "^#" /etc/sendmail.cf |grep -i PrivacyOptions If "novrfy" is not returned, this is a finding.
Add "novrfy" to the "PrivacyOptions" flag in the "/etc/sendmail.cf" file.