Forgotten Passwords: Difference between revisions
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#<nowiki># su fred</nowiki> |
#<nowiki># su fred</nowiki> |
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#execute password command to change password for user "fred" |
#execute password command to change password for user "fred" |
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<nowiki>$ passwd</nowiki> |
#<nowiki>$ passwd</nowiki> |
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#'''logout''' from root account |
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#<nowiki>$ exit</nowiki> |
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#<nowiki># exit</nowiki> |
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#<nowiki>$</nowiki> |
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== Root Password == |
== Root Password == |
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#execute password command to change password for user "fred" |
#execute password command to change password for user "fred" |
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#<nowiki>$ passwd</nowiki> |
#<nowiki>$ passwd</nowiki> |
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#return to booted environment |
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#<nowiki># exit</nowiki> |
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#safely unmount installed system |
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#<nowiki># umount /mnt</nowiki> |
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#if running from installed OS, then '''logout''' from root account |
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== Physical Security == |
== Physical Security == |
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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
