The SMTP service must not have the VRFY feature active.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-240447 | VRAU-SL-000630 | SV-240447r671082_rule | Medium |
| Description |
|---|
| 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. |
| STIG | Date |
|---|---|
| VMware vRealize Automation 7.x SLES Security Technical Implementation Guide | 2021-06-24 |
Details
| Check Text ( C-43680r671080_chk ) |
|---|
| 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. |
| Fix Text (F-43639r671081_fix) |
|---|
| Add "novrfy" to the "PrivacyOptions" flag in /etc/sendmail.cf |