Telia: invalid IP value in SAN DNS field

Telia Company reported an incident involving three invalid certificates issued in 2016, where an IP value was incorrectly stored in the SAN DNS field instead of the SAN IP field. The issue was identified on January 29, 2019, and the certificates were revoked by January 31, 2019. Telia confirmed that the problem arose from a bug in their CA code that copied the CN value to the wrong field. To prevent future occurrences, Telia has implemented automatic testing and regular lint checking. A mass scan of all active certificates revealed additional errors, which are being addressed.

1. 2019-01-29 Telia was informed about the invalid certificates.
2. 2019-01-31 The invalid certificates were revoked.
3. 2019-02-01 Telia conducted a database check and found additional problematic certificates.

1. 2019-02-01 Teliasonera representative — Telia reported the invalid certificates and confirmed their revocation.
2. 2019-02-04 Teliasonera representative — Telia provided a complete incident report detailing the timeline and actions taken.
3. 2019-02-12 Teliasonera representative — Telia completed a mass zlint scan revealing additional errors.
4. 2019-06-28 Fastly representative — Mozilla confirmed that all questions were answered and remediation was complete.