2 Min Read FILE PHOTO: White House Deputy National Security Advisor for Cyber and Emerging Technology Anne Neuberger gives an update on the Biden administration's response to the SolarWinds hack during the daily briefing at the White House in Washington, D.C., U.S. February 17, 2021. REUTERS/Leah Millis WASHINGTON (Reuters) - The top cybersecurity official in the White House on Tuesday directed all government agencies to urgently apply new patches for Microsoft Corp Exchange email servers to head off exploitation by hackers. The rare directive applies to software fixes for four flaws discovered by the U.S. National Security Agency and reported to Microsoft.