Check: IUTN0040
zOS RACF STIG:
IUTN0040
(in versions v6 r43 through v6 r30)
Title
HFS objects for the z/OS UNIX Telnet Server will be properly protected. (Cat II impact)
Discussion
HFS directories and files of the z/OS UNIX Telnet Server provide the configuration and executable properties of this product. Failure to properly secure these objects may lead to unauthorized access resulting in the compromise of the integrity and availability of the operating system environment, ACP, and customer data.
Check Content
Refer to the following report produced by the UNIX System Services Data Collection: - USSCMDS.RPT(IUTN0040) Refer to the following report produced by the IBM Communications Server Data Collection: - PDI(ZUTN0040) The HFS permission bits and user audit bits for each directory and file match or are more restrictive than the specified settings listed in the table. If the guidance is true, this is not a finding. z/OS UNIX TELNET Server HFS Object Security Settings File Permission Bits User Audit Bits /usr/sbin/otelnetd 1740 fff /etc/banner 0744 faf NOTE: The /usr/sbin/otelnetd object is a symbolic link to /usr/lpp/tcpip/sbin/otelnetd. The permission and user audit bits on the target of the symbolic link must have the required settings. The following represents a hierarchy for permission bits from least restrictive to most restrictive: 7 rwx (least restrictive) 6 rw- 3 -wx 2 -w- 5 r-x 4 r-- 1 --x 0 --- (most restrictive) The possible audit bits settings are as follows: f log for failed access attempts a log for failed and successful access - no auditing
Fix Text
The IAO with the assistance of a systems programmer with UID(0) and/or SUPERUSER access, will review the UNIX permission bits and user audit bits on the HFS directories and files for the z/OS UNIX Telnet Server. Ensure they conform to the specifications below: z/OS UNIX TELNET Server HFS Object Security Settings File Permission Bits User Audit Bits /usr/sbin/otelnetd 1740 fff /etc/banner 0744 faf NOTE: The /usr/sbin/otelnetd object is a symbolic link to /usr/lpp/tcpip/sbin/otelnetd. The permission and user audit bits on the target of the symbolic link must have the required settings. The following represents a hierarchy for permission bits from least restrictive to most restrictive: 7 rwx (least restrictive) 6 rw- 3 -wx 2 -w- 5 r-x 4 r-- 1 --x 0 --- (most restrictive) The possible audit bits settings are as follows: f log for failed access attempts a log for failed and successful access - no auditing The following commands can be used (from a user account with an effective UID(0)) to update the permission bits and audit bits: chmod 1740 /usr/lpp/tcpip/sbin/otelnetd chaudit rwx=f /usr/lpp/tcpip/sbin/otelnetd chmod 0744 /etc/banner chaudit w=sf,rx+f /etc/banner
Additional Identifiers
Rule ID: SV-3232r3_rule
Vulnerability ID: V-3232
Group Title: IUTN0040
Expert Comments
CCIs
| Number | Definition |
|---|---|
| CCI-000213 |
The information system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies. |
| CCI-000225 |
The organization employs the concept of least privilege, allowing only authorized accesses for users (and processes acting on behalf of users) which are necessary to accomplish assigned tasks in accordance with organizational missions and business functions. |
| CCI-001499 |
The organization limits privileges to change software resident within software libraries. |
| CCI-002234 |
The information system audits the execution of privileged functions. |