Suddenly I am no longer a sudoer!

Support & Help Requests
1

All of a sudden, when I am trying to sudo a command, I am told my user account doesn’t belong to the sudoers group. :fearful:

I lost all sudo privileges and have no idea how this was possible since I have not issued any commands that would take me away from this group.

The little I can do on the machine right now to investigate what could possible have gone wrong, doesn’t help much. I am still listed on /etc/passwd as a 1000:1000 UID/GID user. So that’s ok. I can also see in /etc/group my user group. So nothing out of the ordinary here. On the Panel, under System > Administration > Users and Groups, I can click the Manage Groups button and when I scroll down to the sudo group and hit Properties, I can see my user name, but it is not checked.

I cannot login as root, and all dialog boxes asking me for authentication for privilege escalation fail.

What can I do? What happened? Is the sudoers file corrupt? What? Please don’t tell me I have to reinstall the operating system! I just don’t have the internet to do it. At 60 USD for 2GB over here in Angola, having to reinstall Ubuntu is impossible at this point.

2

What about recovery mode or…

https://help.ubuntu.com/community/LiveCdRecovery

1 Like
3

Your user is no longer a member of group “sudo”. Verify by looking in /etc/group for sudo: “sudo:x:27:” should be “sudo:x:27:your_user_name”.

You can fix your problem by booting into recovery mode. See instructions here:

3 Likes
4

I tried Recovery mode from the GRUB menu, but my USB keyboard apparently doesn’t work after I get to the Recovery Mode main menu. It’s weird. I can’t cycle through the options, or choose anything, despite the keyboard working fine earlier in the grub menu.

I’ll have to write down that webpage (I don’t have a printer) and will see what I can do.

5

Plug in a keyboard or maybe check your bios. There should be a option for it.

6

Ok. The live cd recovery mode helped and I was able to add my user account back to the sudoers group. Thank you @anon42388993.

And thank you also @Dave_Barnes; your post helped me understand what went wrong.
As part of my study of bash scripting I am following the Linux Command Line and Scripting Bible, 3rd Edition, by Richard Blum et al, from WILEY. Early this morning (some 12 hours ago) I was going through chapter 7 and the book has a major, major error: it tells you that to add a user to a group you can do $ usermod -G group name. Which I did in good faith, while testing it with a new group I had created. :angry:

Looking at the documentation now I can see it in fact requires -a or else my entire group list is replaced.

So it was not just sudo. I got removed from every other group I was previously a member off. I added myself already also to postgres. But the others I just don’t know which groups I should belong. So if anyone could help me pick them apart…

$ ls /etc/group
root:x:0:
daemon:x:1:
bin:x:2:
sys:x:3:
adm:x:4:syslog
tty:x:5:
disk:x:6:
lp:x:7:
mail:x:8:
news:x:9:
uucp:x:10:
man:x:12:
proxy:x:13:
kmem:x:15:
dialout:x:20:
fax:x:21:
voice:x:22:
cdrom:x:24:
floppy:x:25:
tape:x:26:
sudo:x:27:marfig
audio:x:29:pulse
dip:x:30:
www-data:x:33:
backup:x:34:
operator:x:37:
list:x:38:
irc:x:39:
src:x:40:
gnats:x:41:
shadow:x:42:
utmp:x:43:
video:x:44:
sasl:x:45:
plugdev:x:46:
staff:x:50:
games:x:60:
users:x:100:
nogroup:x:65534:
systemd-journal:x:101:
systemd-timesync:x:102:
systemd-network:x:103:
systemd-resolve:x:104:
systemd-bus-proxy:x:105:
input:x:106:
crontab:x:107:
syslog:x:108:
netdev:x:109:
messagebus:x:110:
uuidd:x:111:
ssl-cert:x:112:postgres
lpadmin:x:113:
lightdm:x:114:
nopasswdlogin:x:115:
ntp:x:116:
whoopsie:x:117:
mlocate:x:118:
ssh:x:119:
avahi-autoipd:x:120:
avahi:x:121:
bluetooth:x:122:
scanner:x:123:saned
colord:x:124:
pulse:x:125:
pulse-access:x:126:
rtkit:x:127:
saned:x:128:
marfig:x:1000:
sambashare:x:129:
vboxusers:x:131:
postgres:x:132:marfig
nvidia-persistenced:x:130:
debian-spamd:x:133:
1 Like
7

Yours is basically the same as mine I think and I am the sole user.

root:x:0:
daemon:x:1:
bin:x:2:
sys:x:3:
adm:x:4:syslog,m16
tty:x:5:
disk:x:6:
lp:x:7:
mail:x:8:
news:x:9:
uucp:x:10:
man:x:12:
proxy:x:13:
kmem:x:15:
dialout:x:20:
fax:x:21:
voice:x:22:
cdrom:x:24:m16
floppy:x:25:
tape:x:26:
sudo:x:27:m16
audio:x:29:pulse
dip:x:30:m16
www-data:x:33:
backup:x:34:
operator:x:37:
list:x:38:
irc:x:39:
src:x:40:
gnats:x:41:
shadow:x:42:
utmp:x:43:
video:x:44:
sasl:x:45:
plugdev:x:46:m16
staff:x:50:
games:x:60:
users:x:100:
nogroup:x:65534:
systemd-journal:x:101:
systemd-timesync:x:102:
systemd-network:x:103:
systemd-resolve:x:104:
systemd-bus-proxy:x:105:
input:x:106:
crontab:x:107:
syslog:x:108:
netdev:x:109:
messagebus:x:110:
uuidd:x:111:
ssl-cert:x:112:
lpadmin:x:113:m16
lightdm:x:114:
nopasswdlogin:x:115:
ntp:x:116:
whoopsie:x:117:
mlocate:x:118:
ssh:x:119:
avahi-autoipd:x:120:
avahi:x:121:
bluetooth:x:122:
scanner:x:123:saned
colord:x:124:
pulse:x:125:
pulse-access:x:126:
rtkit:x:127:
saned:x:128:
m16:x:1000:
sambashare:x:129:m16
vboxsf:x:130:
1 Like
8

Thank you @anon42388993, You folks are fantastic!
That will set me right. I believe I will also have to add myself to vboxusers in addition to what I can see in your list.

Cheers! :joy:

$ cat /etc/group | grep marfig
adm:x:4:syslog,marfig
cdrom:x:24:marfig
sudo:x:27:marfig
dip:x:30:marfig
plugdev:x:46:marfig
lpadmin:x:113:marfig
marfig:x:1000:
sambashare:x:129:marfig
vboxusers:x:131:marfig
postgres:x:132:marfig

9

Only if your running VirtualBox and want access to the Host.

Don't forget to check the solve box :slight_smile: