Error :- sudo: effective uid is not 0, is sudo installed setuid root?

We all as a Linux administrator must have come across this error sometime in our lives.

[user@host dir]$ sudo bash
sudo: effective uid is not 0, is sudo installed setuid root?

This happens when sudo does not get the right access permissions.

The Solution for this error is giving the following permissions as root user

chmod u+s /usr/bin/sudo

That Must Sort the issue for CentOS Kind of distros.

 

Advertisements

Safest and the least vulnerable way to add a user to the sudoers with full rights

visudo

demouser ALL=(ALL) PASSWD:ALL, !/bin/su root, !/bin/su -, !/bin/sudo su -, !/bin/su – root, !/bin/sudo su root, !/bin/su, !/usr/bin/passwd, !/usr/bin/passwd root, !/bin/vi /etc/sudoers, !/usr/bin/sudo vi /etc/sudoers, !/usr/sbin/visudo, !/usr/sbin/sudo visudo, !/bin/chmod 777 /etc/sudoers, !/bin/chmod ugo+rwx /etc/sudoers

:wq!

 

How to Send Email from Telnet

We use the “mail.xx.com” as an example.

Be sure to replace with your own domain.

Open your command prompt.

Now, connect with telnet using the following command:

telnet mail.xx.com 25

Some servers also accept helo in place of ehlo.

ehlo xx.com

Type mail

mail from: username@xx.com
rcpt to: friend@hotmail.com, friend2@yahoo.com, friend3@xx.com

To write the message – type data, followed by your subject and message. To end the message, put a period on a line by itself and press enter:

data
Subject: My Telnet Test Email

Hello,

This is an email sent by using the telnet command.

Your friend,
Me

.

quit

Type quit to exit telnet.
HOW TO CHECK OR READ EMAIL WITH TELNET

Open your command prompt.
At the command prompt, type in

telnet xx.com 110

Type user and the email address (username@xx.com) of the user for which you wish to view emails:

user username@xx.com

Then type in pass followed by your password:

pass yourpasswordgoeshere

Type list to bring up a list of your emails:
list
You will see a list of items with labels like “1 897” and “2 5136.” Here is an example:
list
+OK POP3 clients that break here, they violate STD53.

1 897
2 5136
3 1884
4 2973
5 2595
6 3063
7 3509
8 2283
9 1926
10 2763
11 1795
12 2780
13 2342
14 2342
15 2342
16 3833
17 2211
18 793
19 797
20 2599
.

If you wish to read an email message such as 2 5136, you can type the following:

retr 2

If you want to delete a message such as 1 897, type dele 1:

dele 1

When you are done checking your email, type quit.

quit

RESOURCES:-

Telnet on Wikipedia