ubuntu 16.04 – How to check what users can possibly access and control my server?

I have recently got access to a legacy server previously manage by someone else.
Access control and password changing is the priority by now.
I have some shell base knowledge but definitely not a senior sysadmin. And need some guidance and general suggestion about his topic.

So I have root access and I can check the list of users.

I wonder if there’s a way to understand immediately from /etc/passwd contents what are the unix user that could possibly access the system, filtering out the standard user.
System is Ubuntu 16

And I can see from passwd that root is the only user having “/bin/bash”:

root:x:0:0:root:/root:/bin/bash

Other users seems more related to installed services..
So maybe no other users apart root were used before to access the system
Is there a way to check it?

I’m supposing that all users having the last row token like:

:/usr/sbin/nologin
:/bin/false
:[void no chars]

should be system’s service users

Aren’t they?

Thanks for any advice

macos – It seems to take far too long to unlock the “Users & Groups” setting on Mojave than was the case for High Sierra

This has bugged me from the time I did the first upgrade to Mojave (revision 3) under advice not to upgrade from High Sierra when Mojave was first released. I have tried several resets and even a clean install (I’m now on 10.14.6). Compared to High Sierra, it seems to take as long as 3 – 4 minutes to unlock but (without actually having measured it) HS might have only been a minute or so. Even the login at boot time it seems to take longer and I have to type more slowly type in my login than I used too!
I would appreciate please if anyone can provide any suggestion that might help. I have tried already quite a few discussion groups for answers but many refer to other OS’s and other situations not related to mine specifically. I can provide more info if needed.

Prevent logged in users from seeing other registered users information

I’m using Drupal 8 and I have a security requirement to prevent authenticated users from seeing other authenticated users’ profiles.

I have a view which customizes the user profile page of each authenticated user. Each logged in user can see their own profile by accessing the path /user-profile/userId.

Now if the user decided to randomly change the userId in the URL, they cannot access other users’ profiles, since, in the view I have set the ‘Filter Criteria’ to current user. Which works perfectly.

However, if a user decided to randomly change the userId in the path /user/userId they will have access to other users information. What I need to do is to prevent them from accessing /user/userId.

It’s important to mention that the users are free to change their own information using the URL /user/userId/edit

Any suggestions?

database design – What options are available for creating a relationship in an ERD displaying how users given permissions can affect other users?

For my ERD:
What would be the best way to create a relationship (between entities) where a User is given a role that is associated with a chatroom permitting a User to act (banning, kicking etc…) on another User belonging to the same chatroom. Just to note I looked up a concept known as RBAC(Role based access control), but other then the permission I was trying to create a relationship where it will result in a relation containing the user who was banned (or kicked etc…), the person banning and the chatroom where the ban occurred.
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amazon ec2 – Httpd server optimization for 50-100k users

so I currently have an AWS EC2 instance m5.24xlarge that has :

  • 96 vCPU
  • 384 RAM
  • 25 GBPs network

We are currently expecting more than 50 000 concurrent users online, I have added a layer on cloudflare but the issue is I keep getting “server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting” on apache error_log.

What are the best settings for apache in order to handle this kind of traffic?

javascript – Change one SharePoint site link in the Global Navigation redirect to another site for all users except one

For example, a site in the global navigation, when clicked should redirect to another site for all users except one. Also, users who have saved the site as bookmarks should be redirected too when they open the link. How does the .js file look like and where should I add it? Any help appreciated.

sharepoint online – Prevent multiple users from editing the same list item at the same time

I have a list on SharePoint Online, where I need to make sure that only one person can edit a list item at a time. For example, if Person A edits a list item, it MUST be clear to everyone else working, that Person A is working on this list item and no one else should be able to edit this item.

As this is a list I am unable to turn the check in/check out feature on like I could if it was a document library.

Any suggestions would be much appreciated.

haskell – How to change the default Xmonad configuration off all users?

The canonical way to configure Xmonad is by creating the file ~/.xmonad/xmonad.hs

However, I would like to change the default Xmonad configuration for all users, and not just for myself.

I have tried placing a configuration file in /etc/xmonad/xmonad.hs but it didn’t work.

How can I change the system-wide Xmonad configuration?