Microsoft issues urgent dev warning to update .NET installer link

Microsoft is forcing .NET developers to quickly update their apps and developer pipelines so they do not use ‘azureedge.net’ domains to install .NET components, as the domain will soon be unavailable due to the bankruptcy and imminent shutdown of CDN provider Edgio.

Specifically, the domains “dotnetcli.azureedge.net” and “dotnetbuilds.azureedge.net” will be taken offline in the next few months, which could break the functionality of projects relying on the domains.

This includes developers using .NET installers residing on the affected domains, organizations using GitHub Actions or Azure DevOps with custom pipelines using those domains, Docker and script users with files and code referencing the retired domains, and more.

“We maintain multiple Content Delivery Network (CDN) instances for delivering .NET builds. Some end inazureedge.net. These domains are hosted by edg.io, which will soon cease operations due to bankruptcy. We are required to migrate to a new CDN and will be using new domains going forward,” explains Microsoft.

“It is possible that azureedge.net domains will have downtime in the near-term. We expect that these domains will be permanently retired in the first few months of 2025.”

Microsoft recommends that potentially impacted developers search their code, scripts, and configurations for references to azureedge.net and dotnetcli.blob.core.windows.net and replace them with builds.dotnet.microsoft.com.

During the transition, the new domains will be catered by a combination of Edgio, Akamai, and Azure Front Door, as Microsoft works on solidifying the final distribution model with other CDN providers.

CI/CD teams need to ensure GitHub Actions (actions/setup-dotnet) and Azure DevOps tasks are updated to versions supporting the new domains, while updates for Azure DevOps Server are expected in early 2025.

Additionally, given that new CDN domains will now be used, even when configurations are auto-updated, firewalls need to be set to allow traffic from the new locations (builds.dotnet.microsoft.com and ci.dot.net). 

The tech giant notes that the timing is quite unfortunate, as impacted users are requested to take action during the holidays when most IT teams are understaffed.

When asked why Microsoft can’t simply transfer the domains and continue using them, Rich Lander, Program Manager of .NET at Microsoft, said it was not possible.

“We asked the same question. We were told that this option wasn’t being made available. We don’t have more information on that,” explained Lander.

The answer is confusing as Microsoft’s Scott Hanselman confirmed that Microsoft already obtained ownership of the domains, stating that “no other party will ever have access to use these domains.”

By owning the domains and preventing their reuse, the chances of a supply chain compromise for those not migrating their applications are minimal. However, it still doesn’t explain the sudden rush to migrate domains and the risks of operational disruptions.

If you’re impacted, you can follow the issue more closely and access status updates on this GitHub page.

BleepingComputer contacted Microsoft with questions about this .NET domain migration but has not received a reply at this time.