I have a SSD disk with password protection, but the password lost long time ago... so I tried to earse the ATA security with "hdparm" command.

with "hdparm -I", the disk information looks interesting as below:

root@ubuntu:~# hdparm -I /dev/sda


ATA device, with non-removable media
    Model Number:       TX21B10400GE8001                        
    Serial Number:      FG002VTA
    Firmware Revision:  PRO6F515
    Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
    Enabled Supported:
       *    SMART feature set
            Security Mode feature set
    Master password revision code = 65534
    not enabled
    not frozen
    not expired: security count
        supported: enhanced erase
Logical Unit WWN Device Identifier: 50011731001636dc
    NAA     : 5
    IEEE OUI    : 001173
    Unique ID   : 1001636dc
Checksum: correct

As you can see, the disk is in security locked state, and it doesn't support hdparm security mode feature.

When use security unlock command on this disk, the print out like below:

root@ubuntu:~# hdparm --user-master u --security-unlock 123456 /dev/sda

 Issuing SECURITY_UNLOCK command, password="123456", user=user
SECURITY_UNLOCK: Input/output error

I'm wondering is there any other way to unlock this ssd disk and remove the password?

  • You must do it quickly. There is a 2 minute timer. – Thorbjørn Ravn Andersen Aug 9 '15 at 17:10
  • thank you, @ThorbjørnRavnAndersen! Do you mean the disk will be "locked" after the operating system start up? – user3016997 Aug 11 '15 at 13:04
  • It is the "frozen" state. See thomas-krenn.com/en/wiki/SSD_Secure_Erase to learn more. – Thorbjørn Ravn Andersen Aug 11 '15 at 13:56
  • Thank you for your patient feedback, @ThorbjørnRavnAndersen! It's very unlucky that I already lost the user password long time ago, and rebooted the sytem several times. so now every time after I startup the ubuntu system and check this disk, it's in "locked" state, and I can not read/write to this disk anymore. Is there any way to clear the password and do secure ease when the SSD is locked? or is there anyway to unlock the disk without password? – user3016997 Aug 13 '15 at 12:26
  • I do not know. You may want to contact the vendor directly. – Thorbjørn Ravn Andersen Aug 13 '15 at 13:25
up vote 11 down vote accepted

I was able to get this to work on my Western Digital WD20EURS. After piecing together tips from all over google, I was able to get a master password, research the commands of hdparm, and use your example in your original question to resolve my issue. Maybe this will help with you too.

First off, I found a list of master passwords for various brands of drives.

Here are two locations, (replaced with Web Archive versions to avoid link rot)

My Method:

  • Used ESCAPE to cancel Bios HD password request.
  • Booted into CentOS7 CLI (previously installed yum install hdparm)
  • Command hdparm -I /dev/sda to check if drive was "locked" ( -I is capital i )
  • Command hdparm --user-master m --security-unlock PASS /dev/sda
    • m = using master password
    • PASS = for me, typing 'WDC' ten times, with a finishing 'W'
    • found this in the links listed above
  • Command hdparm -I /dev/sda again ( -I is capital i ). This time the drive showed "not locked" (at which I hesitantly rejoiced)
  • Command hdparm --user-master m --security-disable PASS /dev/sda
    • -This should disable the password on the hard drive and allow you to boot without needing a password next time.
  • Then I put the drive back into my windows machine, and I was able to see all the partitions in the drive, erase them, and use this new drive!
  • 2
    Your solution is just slightly terrifying... using the "master" password (a.k.a public value) it should of course never be possible to unlock a locked drive, only to perform a secure erase, which would also remove the user password. If the master password actually lets you unlock the drive and retain the old data, then you can only ask... WTF is the point? In this case it is security theater, there is no actual security or encryption occurring at all on that particular drive model. – JeremyS Feb 29 '16 at 21:00
  • This would be my findings... I was able to remove the password, and retain the data which was previously on this drive. 97% of the drive was encrypted, so that data was not recoverable. But a small partition was not encrypted which only had a few files which related to the cloud system the drive was salvaged from. Nothing exposing sensitive information belonging to the cloud company. The password lock on the drive was more of an advanced step in making the drive less likely to be interchanged by others, or the data easily accessed by others. – Taylor Mar 2 '16 at 3:30
  • 2
    I don't think the design of the password lock on hard drives that was developed decades ago accounted for people eventually figuring out how to hack the drive. It's a rudimentary form of locking either way. In theory, I could swap the logical board of the hard drive with one from the same model, and bypass the password this way as well. As the password is only on the logic board, and not the disk itself. – Taylor Mar 2 '16 at 3:32
  • Is it possible to avoid having the password as a cli parameter? I don't want it to show up in bash history and process list. – donquixote Jan 19 '17 at 15:29
  • zeitgeist.se/2014/09/07/… there is actually a setting, "MASTER PASSWORD CAPABILITY", that defines what you can do with the master password! – donquixote Jan 20 '17 at 23:53

Try using the master password to secure-erase the disk. Performing a secure erase will reset the user password. You can find lists of default master passwords by vendor through google searches. For example, this web site may be useful:


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