Security News > 2024 > March > 17,000+ Microsoft Exchange servers in Germany are vulnerable to attack, BSI warns

Around 12% of the 45,000 or so Microsoft Exchange servers in Germany that can be accessed from the Internet without restrictions "Are so outdated that security updates are no longer offered for them," the German Federal Office for Information Security has warned today.

The BSI worries about attackers breaching those servers by exploiting CVE-2024-21410, a critical elevation of privilege bug that allows attackers to learn a targeted user's NTLM credentials and "Relay" them to authenticate themselves to a vulnerable Exchange Server as the user.

This means that at least 17,000 instances of Microsoft Exchange servers in Germany - and likely more of them - are vulnerable to one or more critical vulnerabilities.

How many more vulnerable Microsoft Exchange servers are out there?

The Shadowserver Foundation currently detects over 17,800+ internet-facing Exchange Servers around the world vulnerable to CVE-2024-21410, 73,300+ possibly vulnerable to CVE-2024-21410, and 70,000+ vulnerable to CVE-2024-26198.

BSI said that its CERT has been notifying network operators in Germany via email about IP addresses in their networks where known vulnerable Exchange servers are located.

News URL

https://www.helpnetsecurity.com/2024/03/26/vulnerable-microsoft-exchange-servers/