# Execution with Unnecessary Privileges (CWE-250)

The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.

**Stack:** Docker

- Prevalence: High Frequently exploited
- Impact: Critical 3 critical-severity rules
- Prevention: Documented 10 fix examples

**OWASP:** Broken Access Control (A01:2021-Broken Access Control) - #1

## Description

New weaknesses can be exposed because running with extra privileges gives the product access to resources that are not necessary. In addition, if an attacker can trigger the operation with the higher privileges, the attacker might gain root or administrator privileges.

## Prevention

### Docker

Add a USER instruction before CMD/ENTRYPOINT to run as non-root

Use a non-root user and restrictive file permissions instead of USER root or chmod 777

## Warning Signs

- [HIGH] No USER instruction before CMD/ENTRYPOINT - container runs as root
- [HIGH] CMD or ENTRYPOINT without a preceding USER instruction
- [HIGH] Dockerfile contains ...: ...
- [HIGH] explicit root user and overly permissive chmod 777 permissions

## Consequences

- Gain Privileges
- Execute Unauthorized Code
- Read Application Data
- Modify Application Data

## Mitigations

- Run your code using the lowest privileges that are required to accomplish the necessary tasks
- Identify the minimum access rights your component requires, and only grant it those rights
- Consider using a Just-In-Time (JIT) privilege model

## Detection

- Total rules: 10
- Critical: 3
- Languages: dockerfile, yaml

## Rules by Language

### Dockerfile (2 rules)

- **Container runs as root** [HIGH]: Detects CMD or ENTRYPOINT without a preceding USER instruction.
The container will run as root, which is a security risk.
  - Remediation: Add a USER instruction before CMD/ENTRYPOINT to run as a non-root user.

```dockerfile
USER appuser
CMD ["node", "server.js"]
```

Learn more: https://shoulder.dev/learn/docker/cwe-250/missing-user
- **Docker User and File Permissions** [HIGH]: Detects explicit root user and overly permissive chmod 777 permissions.
  - Remediation: Use a non-root user and restrictive file permissions.

```dockerfile
RUN adduser -D appuser
USER appuser
```

Learn more: https://shoulder.dev/learn/docker/cwe-250/user-permissions