Details can be found in the Microsoft’s Security Response Center blog. If you are unable to patch, implement an IIS Re-Write Rule and disable Unified Messaging (UM), Exchange Control Panel (ECP) VDir, and Offline Address Book (OAB) VDir Services. Details can be found on Microsoft’s Exchange Team blog. Patch all on-premise Microsoft Exchanged servers in your environment with the relevant security update. It does NOT ensure that an adversary has not already exploited the vulnerabilities. It is important to note that patching only protects your organization from being exploited by the vulnerabilities going forward. One actor is installing a new ransomware variant called DearCry. UPDATE: Other threat actors are now taking advantage of the persistence established by Hafnium to conduct a range of attacks. įor an overview of HAFNIUM, and advice on how you should respond, watch this short video from Mat Gangwer, the head of the Sophos Managed Threat Response (MTR) team.įor details of the Sophos protections against the exploitation of these vulnerabilities, click here.

These vulnerabilities are being actively exploited in the wild.ĬISA also issued an emergency directive urging organizations to patch on-premises Exchange Servers and search their networks for indicators of attack. A remote attacker can exploit three remote code execution vulnerabilities-CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065-to take control of an affected system and can exploit one vulnerability-CVE-2021-26855-to obtain access to sensitive information. Microsoft has released out-of-band security updates to address vulnerabilities affecting Microsoft Exchange Server 2013, 2016, and 2019. These vulnerabilities are being actively exploited in the wild by HAFNIUM, a threat actor believed to be a nation state.

On March 2nd, zero-day vulnerabilities affecting Microsoft Exchange were publicly disclosed. The updates address bugs reported to Microsoft by the NSA and are considered urgent fixes that should be addressed immediately. Update: Microsoft released new security updates for Exchange Server on April 13 th ( CVE-2021-28480, 28481, 28482, and 28483).

Msert log file location