For the second time in two weeks, Microsoft Azure’s multi-factor authentication system is down.
ZDNet on Tuesday noted the outage, which prevents some users from logging into their Office 365 accounts.
We’re investigating an issue where users may be unable to sign in using Multi-Factor Authorization (MFA). All details can be found under Service Incident (SI) #MO165847
— Microsoft 365 Status (@MSFT365Status) November 27, 2018
Here’s an update from the Azure status page:
SUMMARY OF IMPACT: Starting at 14:25 UTC on 27 Nov 2018, customers using Multi-Factor Authentication (MFA) may experience intermittent issues signing into Azure resources, such as Azure Active Directory, when MFA is required by policy. Impacted customers may encounter timeout errors.
CURRENT STATUS: Engineers found that an earlier DNS issue had resulted in failures for a large volume of sign-in requests. This DNS issue has been mitigated. Engineers are recycling all backend services to provide temporary mitigation, and we continue to work on full recovery.
Problems with multi-factor authentication —which generally involves two steps to enter a known password as well as a unique code delivered to one’s phone — plagued Office 365 users on Nov. 19. The outage was blamed on three independent root causes, including latency and response processing issues.
We’ll update this post if we learn more about Tuesday’s outage.