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Remove non trusted certificates

I get a message of dnsdun non trusted certificate. When I click on details it says zz.app. how do I remove this certificate from my iphone 13. I have erased and reset the phone but problem is still there after restoring from backup.

iPhone 13, iOS 16

Posted on Sep 13, 2022 6:11 AM

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Question marked as Top-ranking reply

Posted on Sep 16, 2022 8:53 PM

Okay, the error you’re reporting here is likely a subscribed calendar, the target domain for the subscribed calendar appears misconfigured, and this stuff is ~unrelated to the trust store, and the zz app stuff is another domain associated with the same domain that you’re having issues with. (There are a gazillion top-level domains like the familiar com, net, and org around, and app is one of the many others.)

13 replies
Question marked as Top-ranking reply

Sep 16, 2022 8:53 PM in response to Viddavisda

Okay, the error you’re reporting here is likely a subscribed calendar, the target domain for the subscribed calendar appears misconfigured, and this stuff is ~unrelated to the trust store, and the zz app stuff is another domain associated with the same domain that you’re having issues with. (There are a gazillion top-level domains like the familiar com, net, and org around, and app is one of the many others.)

Sep 15, 2022 3:59 PM in response to Viddavisda

Hi Viddavisda,


Thanks for using Apple Support Communities. Are you using a manage device from a school or from your job? If so, you can see how to remove any configuration profiles here: Install or remove configuration profiles on iPhone - Apple Support


"You can see the profiles you have installed in Settings  > General > VPN & Device Management. If you delete a profile, all of the settings, apps, and data associated with the profile are also deleted."


Please also take a look at the following: Trust manually installed certificate profiles in iOS and iPadOS - Apple Support (IN)


Cheers.



Sep 16, 2022 3:19 PM in response to Viddavisda

That's likely a subscribed calendar.


Check for and remove any calendar subscriptions you don't recognize from the list of subscribed calendars.


To check: open Calendar app, select the Calendars button at the bottom center, and look for a block of Subscribed Calendars.


Details: Delete spam calendars and events on iPhone - Apple Support


Sep 16, 2022 7:57 AM in response to Viddavisda

Hey there Viddavisda,


As you mentioned you restored your iPhone from an iCloud backup, this would make your iPhone as it was when you made the backup. We also don't recommend restoring from a backup as a valid troubleshooting step for the question you're asking.


Moving forward with troubleshooting, we wanted to confirm a few things based on the details you shared so far, along with the links shared earlier:


  1. Do you have any provides currently installed if you check under Settings  > General > VPN & Device Management?
  2. Where exactly are you seeing the message regarding 'dnsdun non trusted certificate', and when did it start to show?
  3. Did you purchase your iPhone used, or brand new from an authorized Apple reseller?
  4. What do you see under Settings > General > About > Certificate Trust Settings?


Have a good one!

Sep 16, 2022 3:08 PM in response to bruno75

Thank you for your reply.


1. I have no manually installed profiles


2.This is the message I see. I have been getting this for at least a month. I also had the same problem about a year ago which resolved itself with an iOS update


this is what I see when I click details:



3 I bought my phone new


4


I hope you can help further. Thank you!

Sep 15, 2022 6:31 PM in response to Keisha_Keisha

It is my personal phone I don’t know how to sign in to a work or school account. I don’t know what dnsdun or zz.app is or how it got there. I get this alert nanny times a day. I was hoping it would go away when I installed iOS 16 but it didn’t. I reset my phone and erased all its contents but the problem persisted when I restored from my iCloud backup.

Sep 16, 2022 4:15 PM in response to Viddavisda

Viddavisda wrote:

Thank you for your suggestion.

I’d like to try disabling the calendars first to see if it will solve the issue. Do you think it would work as a temporary fix? That way I can zero in on which calendar is causing the problem.


Do you have a subscribed calendar? A subscribed calendar, specifically. Not one of the other types of calendars. It'll show in a block labeled as a subscribed calendar. Most folks don't have these. There's a picture of a subscribed calendar block here. If you do not, then I'd rather not waste everybody's time here. If you do have a subscribed calendar, then I can probably explain a little more.

Sep 16, 2022 5:49 PM in response to MrHoffman

Yes I have a few subscribed calendars such as US Holidays, Earth Seasons and a calendar from my place of work. I have disabled them and am waiting to see if the issue resolves. Someone else in this thread has weighed in that zz.app has not upgraded its compatibility with current versions of iOS. Do you know if these components are at the root of some of these subscribed calendars. Thank you for your time and input.

Sep 16, 2022 6:30 PM in response to Viddavisda

Viddavisda wrote:

Yes I have a few subscribed calendars such as US Holidays, Earth Seasons and a calendar from my place of work. I have disabled them and am waiting to see if the issue resolves. Someone else in this thread has weighed in that zz.app has not upgraded its compatibility with current versions of iOS. Do you know if these components are at the root of some of these subscribed calendars. Thank you for your time and input.


As I was apparently unclear, I suspect the fundamental issue is a subscribed calendar.


Does the information available for any of the subscribed calendars match the domains shown?

Sep 16, 2022 8:45 PM in response to MrHoffman

At first I could not figure out how to find the domain for the subscribed calendar. Nothing was apparent in the calendar app. Then I went to General Settings / Calendars / Accounts / Subscribed Calendars and found that EarthSeasons had a server with dnssdun.com


I have still been getting the “Cannot Identify Server”messages with the calendar disabled, so I will now unsubscribe and see if that does the trick.

Remove non trusted certificates

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