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Can't access Mozilla Addons page due to key pinning failue

  • 5 replies
  • 3 have this problem
  • 12 views
  • Last reply by Stefan

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I have set up a fresh install of Ubuntu 22.04 and logged into Firefox. However it didn't sync my extensions and if I try to access addons.mozilla.org, I get a MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE error (screenshot attached).

This did not happen, when I did the same thing with a fresh Windows installation 2 hours earlier (I set up a dualboot system). I already tried logging out and in again and removing SiteSecurityServiceState.txt and ~/.mozilla, as well as emptying cache and deleting cookies without success.

I have set up a fresh install of Ubuntu 22.04 and logged into Firefox. However it didn't sync my extensions and if I try to access addons.mozilla.org, I get a MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE error (screenshot attached). This did not happen, when I did the same thing with a fresh Windows installation 2 hours earlier (I set up a dualboot system). I already tried logging out and in again and removing SiteSecurityServiceState.txt and ~/.mozilla, as well as emptying cache and deleting cookies without success.
Attached screenshots

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Same problem on Arch Linux 6.2.2; FF 110.0.1-1

I have not noticed any other sites besides addons.mozilla.org that yield this error.

I can confirm that deleting SiteSecurityServiceState.txt and cert9.db has no effect.

What is really weird is that this does not occur with existing FF profiles. It does with a new profile (that will then, of course, generate its own cert9.db).

I assume something is wrong with either the way FF 110 generates cert9.db or the certificate of addons.mozilla.org or the compatibility between the two. It is also conceivable that it is prevented from actually accessing the certificate, but I do not know how since the old profile works.

I know FF 110 is old (current is 112.0.2-2), but I cannot afford performing a system upgrade and risking messing up my entire system this week.

On a different note, it would be very desirable to be able to work around such evidently erroneous certificate verification failures. In cases not unlike this one this kind of behavior could seriously impair efforts to update the system in question (say, if it blocks the website of the relevant linux distribution for no reason). That does not seem possible any more by design; the new profile does not even show me the certificate, but in the existing profile I can see that there's nothing wrong with it.

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You can check the connection settings.

  • Settings -> General -> Network: Connection -> Settings

If you do not need to use a proxy to connect to internet, select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

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I tried that and cleared the Cache for good measure, no change.

I also haven't noticed any other websites having this problem.

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After a reboot I did for an unrelated reason, I can now access addons.mozilla.org again.

I have no idea, what resolved the issue, but it may be due to me running apt update and apt upgrade again after installing some other packages?

Unsure, if I should mark this thread as solved, when others are still having the same problem