Check: RHEL-08-030200
RHEL 8 STIG:
RHEL-08-030200
(in versions v1 r14 through v1 r5)
Title
The RHEL 8 audit system must be configured to audit any usage of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls. (Cat II impact)
Discussion
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). "Setxattr" is a system call used to set an extended attribute value. "Fsetxattr" is a system call used to set an extended attribute value. This is used to set extended attributes on a file. "Lsetxattr" is a system call used to set an extended attribute value. This is used to set extended attributes on a symbolic link. "Removexattr" is a system call that removes extended attributes. "Fremovexattr" is a system call that removes extended attributes. This is used for removal of extended attributes from a file. "Lremovexattr" is a system call that removes extended attributes. This is used for removal of extended attributes from symbolic links. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210
Check Content
Verify if RHEL 8 is configured to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls by running the following command: $ sudo grep xattr /etc/audit/audit.rules -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod If the command does not return an audit rule for "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" or any of the lines returned are commented out, this is a finding.
Fix Text
Configure RHEL 8 to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod The audit daemon must be restarted for the changes to take effect.
Additional Identifiers
Rule ID: SV-230413r810463_rule
Vulnerability ID: V-230413
Group Title: SRG-OS-000062-GPOS-00031
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000169 |
The information system provides audit record generation capability for the auditable events defined in AU-2 a. at organization-defined information system components. |
Controls
Number | Title |
---|---|
AU-12 |
Audit Generation |