A Russian hacking group, tracked Winter Vivern (aka TA473), has been actively exploiting vulnerabilities (CVE-2022-27926) in unpatched Zimbra instances to gain access to the emails of NATO officials, governments, military personnel, and diplomats.
The CVE-2022-27926 flaw affects Zimbra Collaboration versions 9.0.0, which is used to host publicly facing webmail portals.
The attacker can also use the compromised accounts to carry out lateral phishing attacks and further infiltrate the target organizations TA473 targeted US elected officials and staffers since at least February 2023. The threat actors created bespoke JavaScript payloads designed for each government targets’ webmail portal.
