cyberstrikeus 8.1.12 Collect Use of Privileged Commands (Scored)
Profile Applicability
- Level 2
Description
Monitor privileged programs (those that have the setuid and/or setgid bit set on execution) to determine if unprivileged users are running these commands.
Rationale
Execution of privileged commands by non-privileged users could be an indication of someone trying to gain unauthorized access to the system.
Audit Procedure
Using Command Line
Verify that an audit line for each setuid/setgid program identified in the find command appears in the audit file with the above attributes.
Run the following to find all setuid/setgid programs:
find PART -xdev \( -perm -4000 -o -perm -2000 \) -type f | awk '{print "-a always,exit -F path=" $1 " -F perm=x -F auid>=500 -F auid!=4294967295 -k privileged" }'
Expected Result
An audit line should exist for each setuid/setgid program found by the find command.
Remediation
Using Command Line
To remediate this issue, the system administrator will have to execute a find command to locate all the privileged programs and then add an audit line for each one of them. The audit parameters associated with this are as follows:
-F path=" $1 "- will populate each file name found through the find command and processed by awk.-F perm=x- will write an audit record if the file is executed.-F auid>=500- will write a record if the user executing the command is not a privileged user.-F auid!= 4294967295- will ignore Daemon events
All audit records will be tagged with the identifier "privileged."
find PART -xdev \( -perm -4000 -o -perm -2000 \) -type f | awk '{print "-a always,exit -F path=" $1 " -F perm=x -F auid>=500 -F auid!=4294967295 -k privileged" }'
Next, add those lines to the /etc/audit/audit.rules file.
Default Value
By default, use of privileged commands is not audited.
References
- CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
Profile
Level 2 - Scored