Duo Mobile Access Issues Caused by Expired DigiCert Certificates (Unsupported Devices)

Duo Mobile Access Issues Caused by Expired DigiCert Certificates (Unsupported Devices)

Quick Overview
  • Some older devices may fail Duo authentication due to expired security certificates
  • This impacts devices running unsupported versions of iOS or Android
  • Users may be unable to approve Duo push requests or complete MFA
  • Updating the device OS or replacing the device resolves the issue

Duo Mobile relies on trusted security certificates to securely communicate with Duo services. A recent expiration of DigiCert certificate bundles may prevent Duo Mobile from functioning on devices that are no longer supported by their operating system vendor.

What Is Happening?

Devices running outdated versions of iOS or Android may not trust newer certificate authorities required by Duo Mobile. As a result, Duo authentication requests may fail without warning.

  • Duo push notifications may never arrive
  • The Duo Mobile app may show connection or security errors
  • Multi-factor authentication attempts may fail entirely
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Important
Devices running unsupported operating systems cannot be fixed through app updates alone. Operating system upgrades or device replacement may be required.

Who Is Affected?

This issue affects users who are running Duo Mobile on devices that no longer meet minimum supported operating system requirements.

  • Older iPhones or iPads that cannot upgrade to a supported iOS version
  • Android devices running end-of-life Android versions
  • Devices that have not received security updates in several years
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Tip
Review the Supported iOS and Android Versions KB article to confirm whether your device can continue using Duo Mobile.

What You Need to Do

  1. Check your device’s current iOS or Android version.
  2. Update the operating system if updates are available.
  3. If the device cannot be updated, transition Duo Mobile to a supported device.
  4. Verify Duo authentication after completing updates or device changes.

Additional Duo Help & Troubleshooting

For common Duo Mobile issues, setup assistance, and troubleshooting steps, visit the Duo knowledge base category:

Need Help?

Contact the IT Help Desk at (936) 468-4357 (HELP) for assistance with Duo Mobile or device upgrades.
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