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Exchange Online Servers Hacked Using Malicious OAuth Applications

Microsoft’s 365 Defender Research Team recently investigated an attack in which malicious OAuth applications were deployed on compromised cloud tenants. Initial Access The attacker first needed to compromise a cloud user’s account that had sufficient permissions in order to create a malicious OAuth application. The threat actor did this by launching credential-stuffing attacks against high-risk [...]

Microsoft August 2022 Patch Tuesday: Exchange Server vulnerabilities fixed

Microsoft has released security updates (SUs) for vulnerabilities found in: Exchange Server 2013Exchange Server 2016Exchange Server 2019 The SUs address vulnerabilities responsibly reported to Microsoft by security partners and found through Microsoft’s internal processes. Although we are not aware of any active exploits in the wild, our recommendation is to immediately install these updates to protect your [...]

IceApple exploit framework targeting Microsoft Exchange servers

Stealthy, “highly sophisticated” post-exploitation framework used for data exfiltration likely the work of a state-sponsored threat actor. In late 2021, security researchers on CrowdStrike’s Falcon OverWatch team first detected a modular exploit targeting Microsoft Exchange Servers. Dubbed IceApple, the .NET-based framework has been observed in “distinct locations” and primarily directed toward entities in government, academic [...]

Microsoft Exchange Server Build Numbers and Release Dates

You can use the information in this article to verify the version of Exchange that is running in your organization. This article is organized in sections that correspond to the major releases of Exchange. Each section lists build numbers for each Service Pack (SP), Cumulative Update (CU), Security Update (SU), or Update Rollup (RU) of [...]

2022-11-09T08:57:36-05:00Microsoft Exchange|

Microsoft Exchange Server – Cumulative Updates – April 2022

On April 20, 2022 Microsoft released new Cumulative Updates: Exchange 2016 CU23 and Exchange 2019 CU12. The previous Cumulative Updates were released on September 28, 2021, more than 6 months ago.

Microsoft March 2022 Patch Tuesday: 2 Exchange Server vulnerabilities fixed

The March 2022 SUs for Exchange Server address vulnerabilities responsibly reported by security partners and found through Microsoft’s internal processes. Although we are not aware of any active exploits in the wild, our recommendation is to install these updates immediately. These vulnerabilities affect on-premises Exchange Server, including servers used by customers in Exchange Hybrid mode. Exchange [...]

Microsoft Exchange Server – January 2022 Exchange Server Security Updates

January 2022 Exchange Server Security Updates Microsoft has released security updates for vulnerabilities found in: Exchange Server 2019 Cumulative Update 11 Security Update 3 (KB5008631) Exchange Server 2019 Cumulative Update 10 Security Update 4 (KB5008631) Exchange Server 2016 Cumulative Update 22 Security Update 3 (KB5008631) Exchange Server 2016 Cumulative Update 21 Security Update 4 (KB5008631) Exchange [...]

Microsoft Exchange Server Security – December 2021 CUs Postponed, Critical SUs Needed

Microsoft announces there is no major CU release for December 2021. Microsoft typically releases Cumulative Updates quarterly for Exchange Server 2019, 2016, and 2013. There have been a number of critical Security Updates since the latest September 2021 CUs: see KB5007409, KB5007012. For convenience, here are direct links to the Microsoft downloads for the latest [...]

Microsoft Exchange Server Security – November 2021 Updates

The November 2021 security updates for Exchange Server address vulnerabilities reported by security partners and found through Microsoft’s internal processes. We are aware of limited targeted attacks in the wild using one of vulnerabilities (CVE-2021-42321), which is a post-authentication vulnerability in Exchange 2016 and 2019. Our recommendation is to install these updates immediately to protect your environment. For convenience, [...]