BleepingComputer reports that Microsoft Exchange servers are being targeted by the Cuba ransomware operation with the zero-day OWASSRF exploit, tracked as CVE-2022-41080, which has also been exploited by the Play ransomware gang to evade ProxyNotShell URL rewrite mitigations. Threat operation DEV-0671 has been leveraging the flaw since at least Nov. 17 to compromise Exchange servers with Cuba ransomware payloads, according to a Microsoft report, which comes after CrowdStrike researchers discovered the vulnerability being exploited in the network of cloud computing provider Rackspace. Federal organizations have already been urged by the Cybersecurity and Infrastructure Security Agency to remediate the vulnerability by the end of the month. More than 100 attacks around the world have already been conducted by the Cuba ransomware operation, which has earned over $60 million as of August, an FBI and CISA report revealed. Cuba ransomware was reported by the FBI in late 2021 to have impacted at least 49 U.S. critical infrastructure organizations.