Forgotten Passwords: Difference between revisions
From Info Wiki
Jump to navigationJump to search
(added password change procedures) |
No edit summary |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 6: | Line 6: | ||
#<nowiki># su fred</nowiki> |
#<nowiki># su fred</nowiki> |
||
#execute password command to change password for user "fred" |
#execute password command to change password for user "fred" |
||
<nowiki>$ passwd</nowiki> |
#<nowiki>$ passwd</nowiki> |
||
#'''logout''' from root account |
|||
#<nowiki>$ exit</nowiki> |
|||
#<nowiki># exit</nowiki> |
|||
#<nowiki>$</nowiki> |
|||
== Root Password == |
== Root Password == |
||
| Line 18: | Line 22: | ||
#execute password command to change password for user "fred" |
#execute password command to change password for user "fred" |
||
#<nowiki>$ passwd</nowiki> |
#<nowiki>$ passwd</nowiki> |
||
#return to booted environment |
|||
#<nowiki># exit</nowiki> |
|||
#safely unmount installed system |
|||
#<nowiki># umount /mnt</nowiki> |
|||
#if running from installed OS, then '''logout''' from root account |
|||
== Physical Security == |
|||
It will be seen from the above that any password could be changed on a computer to which physical access is obtained. Any unencrypted '''data''' could then be retrieved from such computer. It is therefore essential to: |
|||
*prevent unwanted physical access to working computers |
|||
*securely erase SSD/HDD storage on computers sent for disposal |
|||
*physically destroy or securely erase unwanted removable media such as floppies, USB, SD, CD/DVD |
|||
Latest revision as of 22:52, 12 September 2016
User Passwords
User passwords can be reset as follows:
- log in as "root"
- switch to user account, eg for user "fred"
- # su fred
- execute password command to change password for user "fred"
- $ passwd
- logout from root account
- $ exit
- # exit
- $
Root Password
Root password can be reset only via booting another Linux on the same computer - either:
- another installed Linux
- a utility USB/CD booted on the computer - these generally run from the root account
- mount the partition containing the root filesystem of the installation for which password reset is required - eg for /dev/sda10
- # mount /dev/sda10 /mnt
- change to the mounted partition
- # chroot /mnt
- execute password command to change password for user "fred"
- $ passwd
- return to booted environment
- # exit
- safely unmount installed system
- # umount /mnt
- if running from installed OS, then logout from root account
Physical Security
It will be seen from the above that any password could be changed on a computer to which physical access is obtained. Any unencrypted data could then be retrieved from such computer. It is therefore essential to:
- prevent unwanted physical access to working computers
- securely erase SSD/HDD storage on computers sent for disposal
- physically destroy or securely erase unwanted removable media such as floppies, USB, SD, CD/DVD
