--- title: Update Microsoft Exchange Server For Important Security Patch description: Update Microsoft Exchange Server For Important Security Patch --- [Securafy Knowledge Hub](https://blog.securafy.com) - [Topics](https://blog.securafy.com/#sf-cover) - [Tools](https://blog.securafy.com/#sf-tools) - [Books & Guides](https://blog.securafy.com/#sf-books) [Talk to Securafy](https://meetings.hubspot.com/securafy/strategy-call) [Topics](https://blog.securafy.com/#sf-cover) [Tools](https://blog.securafy.com/#sf-tools) [Books & Guides](https://blog.securafy.com/#sf-books) [Talk to Securafy](https://meetings.hubspot.com/securafy/strategy-call) [Knowledge Hub](https://blog.securafy.com) / IT Operations IT Operations # Update Microsoft Exchange Server For Important Security Patch Update Microsoft Exchange Server For Important Security Patch ![Randy Hall](https://blog.securafy.com/hubfs/Randy%20Hall%202.png) By Randy Hall Updated Jul 2024 2 min read Share [**](https://www.linkedin.com/sharing/share-offsite/?url=https://blog.securafy.com/2021/11/23/update-microsoft-exchange-server-for-important-security-patch) [**](https://twitter.com/intent/tweet?url=https://blog.securafy.com/2021/11/23/update-microsoft-exchange-server-for-important-security-patch&text=%3Cspan+id%3D%22hs_cos_wrapper_name%22+class%3D%22hs_cos_wrapper+hs_cos_wrapper_meta_field+hs_cos_wrapper_type_text%22+style%3D%22%22+data-hs-cos-general-type%3D%22meta_field%22+data-hs-cos-type%3D%22text%22+%3EUpdate+Microsoft+Exchange+Server+For+Important+Security+Patch%3C%2Fspan%3E) [**](mailto:?subject=%3Cspan+id%3D%22hs_cos_wrapper_name%22+class%3D%22hs_cos_wrapper+hs_cos_wrapper_meta_field+hs_cos_wrapper_type_text%22+style%3D%22%22+data-hs-cos-general-type%3D%22meta_field%22+data-hs-cos-type%3D%22text%22+%3EUpdate+Microsoft+Exchange+Server+For+Important+Security+Patch%3C%2Fspan%3E&body=https://blog.securafy.com/2021/11/23/update-microsoft-exchange-server-for-important-security-patch) ![](https://static.hsstatic.net/BlogImporterAssetsUI/ex/missing-image.png)If you use Exchange Server to handle your company's email then you're probably already aware that a critical security flaw has been discovered that puts the server at risk. The issue is being tracked as CVE-2021-42321 and impacts both Exchange Server 2016 and 2019. Even worse is that Microsoft reports that this issue has been found being exploited in the wild. It is important to note that the security flaw only impacts "on-premises" Exchange Servers including those in Exchange Hybrid mode. So if you use Exchange Online you are not at risk. It has been a tough year for Microsoft Exchange Server. Beginning in March of this year (2021) the company faced a massive wave of attacks that were apparently launched by a number of state-backed threat actors. This first wave relied on ProxyLogon exploits and where they were successful they deployed cryptominers, ransomware, web shells, and other malware strains. They infected as many targets as they could reach. A bit later in July a new wave of attacks began targeting the US EU and the UK. Ultimately the blame for these attacks was laid at the feet of China. These attacks relied heavily on Windows PetitPotam exploits and sought to deploy LockFile ransomware on infected systems. Exchange Server Admins have been feeling the heat this year. The good news is that the wave attacks mentioned above seem to have abated and there's a fix available for the most recently discovered issue. If you run an Exchange Server either on-site or in Hybrid Mode save yourself some time and headaches by downloading and installing the latest patch as soon as possible. There's no need to make more work for yourself than is necessary and you certainly want to do all you can to minimize your risk. Tagged Under IT Operations[Cybersecurity](https://blog.securafy.com/tag/cybersecurity)Business Continuity In This Article Need Help With Your Current Setup? Talk through your current systems, risks, and support gaps with Securafy. [Book a Strategy Call](https://meetings.hubspot.com/securafy/strategy-call) ## Join The Conversation Have a question or perspective on this topic? Add it below. ![Randy Hall](https://blog.securafy.com/hubfs/Randy%20Hall%202.png) About The Author Randy Hall · CEO & Founder Randy Hall is the CEO and Founder of Securafy, with decades of experience helping organizations make smarter, safer decisions about technology. A frequent speaker and instructor at national IT events, Randy has advised thousands of organizations, from startups and SMBs to large enterprises and U.S. government entities, on secure, practical technology adoption. He writes about the decisions business leaders are often expected to make without enough context, including cybersecurity, compliance, AI, cyber insurance, IT strategy, and business resilience. Outside the office, you’ll often find Randy on Lake Erie enjoying time on his 38-foot Chris-Craft. **Writes about:** Cybersecurity strategy, compliance, AI security, business resilience, cyber insurance, SMB risk, IT leadership [More From This Author →](https://blog.securafy.com/author/randyhall) Related Articles Business Continuity [Compliance Risk Assessment: How Downtime Impacts Your Bottom Line](https://blog.securafy.com/compliance-risk-assessment-how-downtime-impacts-your-bottom-line) When systems go down, compliance obligations don't pause—and the financial consequences ... Jul 28, 2026 Compliance [HIPAA Security Rule Changes Are Delayed To 2027: Why Healthcare Organizations Should Not Wait](https://blog.securafy.com/hipaa-security-rule-changes-are-delayed-to-2027-why-healthcare-organizations-should-not-wait) The updated HIPAA Security Rule won't take effect until 2027, but healthcare ... 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