# Ensure no duplicate GIDs exist

The necessity of ensuring unique Group IDs (GIDs) is fundamental to the security model of Linux and other Unix-like operating systems. GIDs are used to manage file permissions and access controls. If multiple group names share the same GID, the system treats them as the same entity regarding permissions. This ambiguity can lead to severe security risks, such as a user gaining unintended access to sensitive files or directories simply by being a member of a group that shares a GID with a more privileged group. This violates the principle of least privilege and can result in data breaches or unauthorized system modifications. The audit script checks for this condition by parsing '/etc/group', counting the occurrences of each GID, and reporting any GID that appears more than once. Remediation is a manual process because an administrator must decide which group to re-assign to a new GID and then perform a system-wide search to update the group ownership of all files associated with the old GID. The recommended state for all security levels (Basic, Moderate, and Strict) is the complete absence of duplicate GIDs. There is no acceptable level of deviation, as any duplication represents a critical misconfiguration and a direct threat to the system's access control integrity.

## Recommended State Configuration

| Security Level | Value |
|----------------|-------|
| **Basic** | `['No duplicate GIDs found']` |
| **Moderate** | `['No duplicate GIDs found']` |
| **Strict** | `['No duplicate GIDs found']` |
| **Type** | `ENUM` |

## Audit Script Working

Bash script that parses the '/etc/group' file to identify any Group IDs (GIDs) that are assigned to more than one group name. The script must only return the numerical value of any duplicate GIDs found, with each duplicate GID on a new line. If no duplicate GIDs exist, the script must produce no output.

## Remediation Script Working

Bash script that returns `false`. Automated remediation for duplicate GIDs is not recommended because it can lead to unintended access control issues and break system integrity. Manual intervention is required to identify which group's GID should be changed and to recursively update the ownership of all associated files and directories across the filesystem.

