IBM z/OS FTP.DATA configuration for the FTP server must have the INACTIVE statement properly set.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-223980SRG-OS-000163-GPOS-00072TSS0-FT-000080SV-223980r970703_rule2025-03-119
Description
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element.
ℹ️ Check
Refer to the file specified on the SYSFTPD DD statement in the FTP started task JCL. If the INACTIVE statement is coded with a value greater than "600", this is a finding. If the INACTIVE statement is coded with a value of "0", this is a finding. If there is no INACTIVE statement coded or the INACTIVE statement is commented out, this is a finding.
✔️ Fix
Code the FTPD configuration file to include the INACTIVE statement with a value between "1" and "600".