Zyxel DX3301-T0 missing Firmware Update "voice"

Marino
Marino Posts: 12  Freshman Member
First Comment Friend Collector
in Home Router

Good morning,
I have a Zyxel DX3301-T0 with Firmware version V5.50(ABVY.3.4)C0.
Since the firmware is a bit old, I would like to update it. I have already downloaded the new Firmware V5.50(ABVY.5.4)C0. There is only one problem. I cannot update it because I cannot see the Firmware Update entry under the Maintenance group.
I also tried with other browsers (Edge, Chrome, FIrefox) looking for this entry but without success. Ideas on this?

Marino

Accepted Solution

  • Marino
    Marino Posts: 12  Freshman Member
    First Comment Friend Collector
    Answer ✓

    In the end I succeeded in the intent, even if I had to apply great subterfuge. Through various searches on google and studies, I discovered that the firmware version that I had also had a vulnerability (shell code execution from root). I can't post details because I think I'm violating some rights.
    [...]
    However, having obtained the password from the supervisor, I deleted the admin user and recreated it in the correct group. I also tested that the reset brings the user back to the user group. Finally I also updated the firmware to the latest version available and I have all the functions available.
    I conclude in all of this that I am very sorry for the Zyxel products that apply these limitations. I hope you can understand how much frustration this situation has created.
    Best regards

«1

All Replies

  • Peter2
    Peter2 Posts: 165  Master Member
    5 Answers First Comment Friend Collector First Anniversary

    You have to be logged in with admin rights to see all options .

    Are you shure to have the firmware with a "C0" ?

  • Marino
    Marino Posts: 12  Freshman Member
    First Comment Friend Collector
    https://community.zyxel.com/en/discussion/comment/77360#Comment_77360
    Screenshot 2025-05-17 202552.png

    To clear up doubts about the version I publish a screenshot. I also confirm that the login is through the administrator username (the device has been reset to factory settings).

  • Peter2
    Peter2 Posts: 165  Master Member
    5 Answers First Comment Friend Collector First Anniversary

    Sorry but thats is impossible . Can you control the righst of Admin in maintainance ? It has to be in admin group .

    I created another admin User to eleminate access via WAN by default .

  • Peter2
    Peter2 Posts: 165  Master Member
    5 Answers First Comment Friend Collector First Anniversary
  • Marino
    Marino Posts: 12  Freshman Member
    First Comment Friend Collector
    edited May 19

    Screenshot 2025-05-19 184341.png

    Unfortunately the admin account is already in the USER group (I just noticed). How can I solve it because even by creating a new user I can't insert it into the admin group?

    Screenshot 2025-05-19 184550.png

    I reset it again (both with the button and via the web interface) and I still find myself with the ADMIN user outside the ADMIN group

  • Peter2
    Peter2 Posts: 165  Master Member
    5 Answers First Comment Friend Collector First Anniversary
    edited May 20

    so "Add new account" and make an admin user the name must not be admin for user with admin rights in admin group …

    But i see one cannot create an admin account with user rights - i think you have to make al real hardware reset pushing the little button on the back for i think 15 seconds . Then the default admin account should reappear again . The device needs a complete new setup after .

  • Marino
    Marino Posts: 12  Freshman Member
    First Comment Friend Collector

    unfortunately I have reset again through the physical button for 15 seconds and more. Even more than one. Unfortunately when I log in admin with the password on the back of the modem I always get the user group as a result. Consequently this limited group does not allow me to create a user with administrative rights.

  • Peter2
    Peter2 Posts: 165  Master Member
    5 Answers First Comment Friend Collector First Anniversary

    This is strange , is it a normal bought device with you as the owner ?

    I would try this trick : create a new user eg with your name , test it and then delete the "false admin" may be the "default admin" reappears .

    2. export the config file and search for ["Username":"admin",] and the values ["Enabled":true,
    "EnableQuickStart":true,] correct them an reimport the config file .

  • Marino
    Marino Posts: 12  Freshman Member
    First Comment Friend Collector
    edited May 21

    I created another user "marino" from admin. Login marino and deleted the admin user. I restart the device and unfortunately the admin user is not recreated.

    Screenshot 2025-05-21 171023.png

    I manually created the admin user. Export the configuration. Edited the config file. Imported the modified config file. Automatically restarted the device after upload. Login via admin.

    Screenshot 2025-05-21 173247.png

    Unfortunately the admin user is still limited to the user group. The only difference is the access group from LAN to LAN/WAN on both users

  • Peter2
    Peter2 Posts: 165  Master Member
    5 Answers First Comment Friend Collector First Anniversary

    So my last idea is to look into the config file if there are other users exept the known two ones .

    This is very strange, may be there is a special unknown history or information about this device …

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