Microsoft disclosed four actively exploited zero-day vulnerabilities being used to attack on-premises versions of Microsoft Exchange Server. The vulnerabilities identified are CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065, all of which affect Microsoft Exchange Server. Exchange Online is not affected. In the attacks observed, the threat actor used these vulnerabilities to access on-premises Exchange servers which enabled access to email accounts, and allowed installation of additional malware to facilitate long-term access to victim environments. Microsoft Threat Intelligence Center (MSTIC) attributes this campaign with high confidence to HAFNIUM, a group assessed to be state-sponsored and operating out of China, based on observed victimology, tactics and procedures.

Minio is a Multi-Cloud Object Storage framework. In a cluster deployment starting with RELEASE.2019-12-17T23-16-33Z and prior to RELEASE.2023-03-20T20-16-18Z, MinIO returns all environment variables, including `MINIO_SECRET_KEY` and `MINIO_ROOT_PASSWORD`, resulting in information disclosure. All users of distributed deployment are impacted. All users are advised to upgrade to RELEASE.2023-03-20T20-16-18Z.