Is AppArmor better than SELinux?

Summary of the Article

AppArmor is a useful Linux security module that can restrict the file-system paths used by an application. It works differently than Security-Enhanced Linux (SELinux) and cannot run at the same time on the same system with SELinux, which comes installed on some Linux distributions.

You cannot run both AppArmor and SELinux at the same time. Each of these are “Major” LSMs, and it is not possible to stack two major LSMs at once.

SELinux policies are more granular and allow for more fine-grained control over system actions compared to AppArmor profiles. SELinux can be configured to enforce different security policies for different users, groups, and processes, providing a higher level of security.

By default, Ubuntu uses AppArmor, another Mandatory Access Control system. To make your Linux system more secure, you can make use of SELinux instead.

Drawbacks of AppArmor:

• AppArmor doesn’t have Multi-Level Security (MLS) and Multi-Category Security (MCS).
• The lack of MCS support makes AppArmor almost ineffective in environments requiring MLS.
• The policy loading also takes longer, so the system starts up slower.

AppArmor (Application Armor) is a Linux security module that protects an operating system and its applications from security threats. To use it, a system administrator associates an AppArmor security profile with each program. Docker expects to find an AppArmor policy loaded and enforced.

Drawbacks of Disabling SELinux:

• On disabling SELinux, each process will have access to files as in a normal Linux System.
• Misuse of rights cannot be prevented. A hacked process can gain access to secret files which are not needed for its original purpose and might be misused. This is a serious issue.

Today, most Linux systems are implementing SELinux — a far-reaching security enhancement that changes the character of system security, but requires that we deal with some additional complexity in managing our systems.

Disadvantages of Running Process with SELinux:

• Increased complexity: SELinux can be complex and difficult to configure, making system administration more difficult.
• Limited compatibility: SELinux is not compatible with all applications, limiting its usefulness in certain contexts.

By default, Security Enhanced Linux (SELinux) is enabled and set to permissive mode for Amazon Linux 2023 (AL2023). In permissive mode, permission denials are logged but not enforced.

AppArmor works by granting access first, then applying restrictions. SELinux, however, restricts access to all applications by default and grants access only to users that present the proper certifications. It uses security profiles based on paths, while SELinux uses security policies based on file labels.

Questions and Answers

1. How useful is AppArmor?

AppArmor is a useful Linux security module that can restrict the file-system paths used by an application.

2. Can AppArmor and SELinux work together?

You cannot run both AppArmor and SELinux at the same time.

3. Does SELinux provide more fine grained security control than AppArmor?

SELinux policies are more granular and allow for more fine-grained control over system actions compared to AppArmor profiles.

4. Does Ubuntu use AppArmor or SELinux?

By default, Ubuntu uses AppArmor, another Mandatory Access Control system.

5. What are the disadvantages of AppArmor?

Drawbacks of AppArmor: It doesn’t have Multi-Level Security (MLS) and Multi-Category Security (MCS), and the policy loading takes longer, making the system start up slower.

6. What does AppArmor protect against?

AppArmor (Application Armor) is a Linux security module that protects an operating system and its applications from security threats.

7. Why not to use SELinux?

Drawbacks of disabling SELinux include the ability for each process to have access to files as in a normal Linux System, which can lead to misuse of rights and potential security issues.

8. Is SELinux still being used?

Today, most Linux systems are implementing SELinux as a far-reaching security enhancement.

9. What is the disadvantage of SELinux?

Disadvantages of running processes with SELinux include increased complexity in system administration and limited compatibility with certain applications.

10. Does Amazon Linux use SELinux?

By default, Security Enhanced Linux (SELinux) is enabled and set to permissive mode for Amazon Linux 2023 (AL2023).

11. What is the difference between Kubernetes AppArmor and SELinux?

AppArmor works by granting access first, then applying restrictions, while SELinux restricts access to all applications by default and grants access only to users that present the proper certifications. Additionally, AppArmor uses security profiles based on paths, while SELinux uses security policies based on file labels.