STIGQter: STIG Summary: IBM z/OS TSS Security Technical Implementation Guide Version: 8 Release: 2 Benchmark Date: 23 Apr 2021: STIGQter: STIG Summary: IBM z/OS TSS Security Technical Implementation Guide Version: 8 Release: 2 Benchmark Date: 23 Apr 2021:SV-224082r561402_rule
V-224082
SRG-OS-000080-GPOS-00048
TSS0-US-000090
CAT II
10
Configure the UNIX permission bits and user audit bits on each of the HFS directories in the table SYSTEM DIRECTORY SECURITY SETTINGS below to be equal or more restrictive.
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
SYSTEM DIRECTORY SECURITY SETTINGS
DIRECTORY PERMISSION BITS USER AUDIT BITS FUNCTION
/ [root] 755 faf Root level of all file systems. Holds critical mount points.
/bin 1755 fff Shell scripts and executables for basic functions
/dev 1755 fff Character-special files used when logging into the OMVS shell and during C language program compilation.
Files are created during system IPL and on a per-demand basis.
/etc 1755 faf Configuration programs and files (usually with locally customized data) used by z/OS UNIX and other product initialization processes
/lib 1755 fff System libraries including dynamic link libraries and files for static linking
/samples 1755 fff Sample configuration and other files
/tmp 1777 fff Temporary data used by daemons, servers, and users. Note: /tmp must have the sticky bit on to restrict file renames and deletions.
/u 1755 fff Mount point for user home directories and optionally for third-party software and other local site files
/usr 1755 fff Shell scripts, executables, help (man) files and other data. Contains sub-directories (e.g., lpp) and mount points used by program products that may be in separate file systems.
/var 1775 fff Dynamic data used internally by products and by elements and features of z/OS UNIX.
The following commands are a sample of the commands to be used (from a user account with an effective UID(0)) to update the permission bits and audit bits:
chmod 0755 /
chaudit w=sf,rx+f /
chmod 0755 /bin
chaudit rwx=f /bin
From the ISPF Command Shell enter:
omvs
enter CD /
enter ls -alW
If 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 SYSTEM DIRECTORY SECURITY SETTINGS table below, this is not a finding.
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
SYSTEM DIRECTORY SECURITY SETTINGS
DIRECTORY PERMISSION BITS USER AUDIT BITS FUNCTION
/ [root] 755 faf Root level of all file systems. Holds critical mount points.
/bin 1755 fff Shell scripts and executables for basic functions
/dev 1755 fff Character-special files used when logging into the OMVS shell and during C language program compilation.
Files are created during system IPL and on a per-demand basis.
/etc 1755 faf Configuration programs and files (usually with locally customized data) used by z/OS UNIX and other product initialization processes
/lib 1755 fff System libraries including dynamic link libraries and files for static linking
/samples 1755 fff Sample configuration and other files
/tmp 1777 fff Temporary data used by daemons, servers, and users. Note: /tmp must have the sticky bit on to restrict file renames and deletions.
/u 1755 fff Mount point for user home directories and optionally for third-party software and other local site files
/usr 1755 fff Shell scripts, executables, help (man) files and other data. Contains sub-directories (e.g., lpp) and mount points used by program products that may be in separate file systems.
/var 1775 fff Dynamic data used internally by products and by elements and features of z/OS UNIX.
V-224082
False
TSS0-US-000090
From the ISPF Command Shell enter:
omvs
enter CD /
enter ls -alW
If 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 SYSTEM DIRECTORY SECURITY SETTINGS table below, this is not a finding.
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
SYSTEM DIRECTORY SECURITY SETTINGS
DIRECTORY PERMISSION BITS USER AUDIT BITS FUNCTION
/ [root] 755 faf Root level of all file systems. Holds critical mount points.
/bin 1755 fff Shell scripts and executables for basic functions
/dev 1755 fff Character-special files used when logging into the OMVS shell and during C language program compilation.
Files are created during system IPL and on a per-demand basis.
/etc 1755 faf Configuration programs and files (usually with locally customized data) used by z/OS UNIX and other product initialization processes
/lib 1755 fff System libraries including dynamic link libraries and files for static linking
/samples 1755 fff Sample configuration and other files
/tmp 1777 fff Temporary data used by daemons, servers, and users. Note: /tmp must have the sticky bit on to restrict file renames and deletions.
/u 1755 fff Mount point for user home directories and optionally for third-party software and other local site files
/usr 1755 fff Shell scripts, executables, help (man) files and other data. Contains sub-directories (e.g., lpp) and mount points used by program products that may be in separate file systems.
/var 1775 fff Dynamic data used internally by products and by elements and features of z/OS UNIX.
M
4102