1

On linux ami the only way to easily run systemctl for my server is by running

sudo systemctl start node

In the service:

/etc/systemd/system/node.service

sudo seems to be mandatory for the 'enable', 'status', 'start' and 'stop' systemctl commands to work (I know there are tutorials out there to run as 'user' and not need to use sudo, but I have not been able to get them to work)

I have

 [Service]
 User=ec2-user

So the user is 'ec2-user' and no 'root'. So I am wondering if although I am running systemctl as root, the service itself is run as ec-2user.

Potential security risks as I understand include end-user using the webapp and uploading malicious files through the API stack - those files may then save my server for specific end-points (like when uploading a PDF or image), then this is where it gets hazy for me, but if the end-user instead uploaded 'some kind of script' to put malware onto the server's disk instead of uploading a PDF or image.... then.... because systemctl was run as root, then the script would have might have the permissions to execute on my server or do some kind of 'command and control'?

Or is the fact that systemctl is run as 'ec2-user' and not 'root' prevent malicious files from being uploaded and executed on the stack? And I am therefore safe to run sudo systemctl ... commands so long as the [Service] user is non-root ?

This is a general question, but to have one specific example, I know ImageMagick has been riddled with this kind of security vulnerability

https://imagetragick.com/

https://us-cert.cisa.gov/ncas/current-activity/2016/05/04/ImageMagick-Vulnerability

user1709076
  • 149
  • 7

1 Answers1

3

Services like web servers should be run without escalated privileges, exactly for the reasons that you describe in your question.

While it is true that you must be root to run systemctl, the user that the web server runs under is usually another user with lower privileges. In the case of apache or apache2, the user is is often www-data, apache, or nobody.

For more information on how to see which user apache/apache2 is running as, see https://serverfault.com/questions/125865/finding-out-what-user-apache-is-running-as

For more information on starting/stopping apache/apache2 using systemctl, see https://unix.stackexchange.com/questions/290923/apache-and-systemctl-status

mti2935
  • 19,868
  • 2
  • 45
  • 64