Following the discovery of two critical vulnerabilities affecting PHP, the NRO and ASO websites have been temporarily taken offline as a precaution:

https://www.nro.net/
https://www.aso.icann.org/

While there is no indication that this vulnerability has been exploited, the sites have been taken offline to test and apply the relevant patches.

Visit the following status page for further updates and more information: 

https://status.ripe.net/