cyberstrikeus 6.1.14 Audit SGID executables (Not Scored)
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
The owner of a file can set the file's permissions to run with the owner's or group's permissions, even if the user running the program is not the owner or a member of the group. The most common reason for a SGID program is to enable users to perform functions (such as changing their password) that require root privileges.
Rationale
There are valid reasons for SGID programs, but it is important to identify and review such programs to ensure they are legitimate. Review the files returned by the action in the audit section and check to see if system binaries have a different md5 checksum than what from the package. This is an indication that the binary may have been replaced.
Audit Procedure
Run the following command to list SGID files:
df --local -P | awk {'if (NR!=1) print $6'} | xargs -I '{}' find '{}' -xdev -type f -perm -2000
The command above only searches local filesystems, there may still be compromised items on network mounted partitions. Additionally the --local option to df is not universal to all versions, it can be omitted to search all filesystems on a system including network mounted filesystems or the following command can be run manually for each partition:
find <partition> -xdev -type f -perm -2000
Expected Result
Review the list of SGID files and ensure no rogue SGID programs have been introduced into the system.
Remediation
Ensure that no rogue SGID programs have been introduced into the system. Review the files returned by the action in the Audit section and confirm the integrity of these binaries.
Default Value
Not applicable.
References
None
CIS Controls
5.1 Minimize And Sparingly Use Administrative Privileges - Minimize administrative privileges and only use administrative accounts when they are required. Implement focused auditing on the use of administrative privileged functions and monitor for anomalous behavior.
Profile
- Level 1