Microsoft Exchange Managed Availability services are also disabled to prevent mitigation regression. The two vulnerabilities are: CVE-2022-41040: A server-side request forgery (SSRF) vulnerability. This update is available through Windows Update. This issue occurs also in privacy window modes (such asInPrivate mode in Microsoft Edge). You run Exchange Server older than Exchange 2013 (Exchange 2003, Exchange 2007, or Exchange 2010). Released: November 2021 Exchange Server Security Updates, Repair failed installations of Exchange Cumulative and Security updates. Proxy logon vulnerabilities are described in CVE-2021-26855, 26858, 26857, and 27065. There will be have a corresponding item IPM.FileSet in OAB folder of SystemMailbox {bb558c35-97f1-4cb9-8ff7-d53741dc928c}@domaincorp.com mailbox with subject <oab_guid>. Sharing best practices for building any app with .NET. Volexity identified a large amount of data being sent to IP addresses it believed were not tied to legitimate users. The advanced monitoring capabilities of Exchange are also disabled, due to disabling Microsoft Exchange Managed Availability services. According to Microsoft, four of these vulnerabilities have already been exploited in limited targeted attacks . We are releasing updates for Exchange Server 2010 for defense-in-depth purposes. The flaw, indexed as CVE-2021-26855, is a server-side request forgery vulnerability that allows an attacker to send arbitrary HTTP requests and authenticates them as the Exchange server. The disclosure follows last month's out-of-band (OOB) security update which addressed four zero-day vulnerabilities in Exchange Server that were exploited in the . Examples. Microsoft Exchange Managed Availability services are also disabled to prevent mitigation regression. Will Microsoft be releasing November 2021 SUs for older (unsupported) versions of Exchange CUs?No. Cybersecurity Tips + Vulnerability Alerts, Microsoft Exchange Server Vulnerability Advisory | April 2021, zero-day vulnerabilities announced in early March, NSA discovers critical Exchange Server vulnerabilities, patch now, CVE-2021-28480, CVE-2021-28481, CVE-2021-28482, CVE-2021-28483: Four Critical Microsoft Exchange Server Vulnerabilities Patched in April Patch Tuesday, Emergency Directive 21-02, Supplemental Direction v2. It could authenticate by exploiting the CVE-2021-26855 SSRF vulnerability or by compromising a legitimate admin's . Customers should choose one of the following mitigation strategies based on your organizations priorities: Recommended solution: Install the security patch. Fix the vulnerability if found:.\Test-CVE-2021-34470.ps1 -ApplyFix Search your IIS logs to identify whether or not the files identified as malicious have been accessed. To determine if you are at risk you need to open the vulnerability table and look for CVE-2021-26855 since all remaining flaws can only be exploited after this one has been compromised. This script checks targeted exchange servers for signs of the proxy logon compromise. The zero-day vulnerability is being actively exploited by threat actors to target Windows users. Detecting CVE-2021-26855 in vendor network Step 2: Select "Apply Filters" in the top right If there is a mismatch between the URL Rewrite module and IIS version, ExchangeMitigations.ps1 will not apply the mitigation for CVE-2021-26855. To learn more about these vulnerabilities, see the following Common Vulnerabilities and Exposures (CVE): CVE-2021-26412 Microsoft Exchange Server Remote Code Execution Vulnerability CVE-2021-27078 Microsoft Exchange Server Remote Code Execution Vulnerability This script contains mitigations to help address the following vulnerabilities: This script is to be executed via an elevated Exchange PowerShell Session or elevated Exchange Management Shell. Did Microsoft release a CVE-2021-42321 mitigation via either Exchange Server Emergency Mitigation Service or the stand-alone EOMT tool?We have not released mitigations for this vulnerability. This issue occurs because browser restrictions prevent the response from being recorded. If you encounter errors during installation, see the SetupAssist script. Microsoft released details on an active state-sponsored threat campaign exploiting four zero-day vulnerabilities in on-premises instances of Microsoft Exchange Server. No exploits have yet been observed of the vulnerabilities, but their critical nature requires fast action. You can get the standalone update package through the Microsoft Download Center. Limited exploitation of these vulnerabilities in the wild has been reported. F43DACE881230595678BEC7A0C24E17618CBA6196CDE86D80058B2BCF3A263B6, 5DBF2F3C65CA9B5D6A4E1B30EEC1327C17737E6ADA0B528BB83CD2D90ED3C8E9, 9B1FCB9DCCBC398F3E894A1BBD34FD6583F315F743A205B889FE9755D3F4F807, Exchange Server 2016 Cumulative Update 16, 992E059C01872BEE7FB2A3082FEE8C630332450220F9770BC2BBAC3769E9D2A8, Exchange Server 2016 Cumulative Update 15, 0208AB1E3D1B9884D67130B355AB3A963DD3BB70FAECA12D1BE102DC78A0F38D, Exchange Server 2016 Cumulative Update 14, 0DFB6E97D4BE071D696C0CA7BF0F7DF06C9EB323A3E048038E69CD82A31CE5C4, EC716655A910E204D5528B6017E6647A9B83C38714360138CD3FD036C2791A41, 1FAF5C2F995231A203A7C3FE97052AFD7924A6A57AC52155AC72DF825AB654C9, Exchange Server 2016 Cumulative Update 19, 26BBEA76A03363F6CFCFA60EC384BCC5DE021F06765FEAE1941EDD7A0C2AFFF4, Exchange Server 2016 Cumulative Update 18, 7C7DA7E41628445FB7B6E8314F38530F0CC1F738153963CFFEA2D52F4E1E6B94, Exchange Server 2013 Cumulative Update 23, 42ACE35CB2BF1202C6ABC2F3BCF689A244C9566ED9CC466D2AFBE6ED691D42E3, DEFAFA95825644D7598171C820FB77A7DDBEE31183B51018424F333D4F65236A, Exchange Server 2016 Cumulative Update 17, 4E83567ED4202C7784654C2707D15AB384EFEAA51121D5D0918BCC040CBFA91A, Exchange Server 2016 Cumulative Update 13, 82DDB7B2B1E3C9D9FFB47C2A1F4813AF6D177F5748D2829F067F5D92EF1F38BB, Exchange Server 2016 Cumulative Update 12, 295325D460462F5A60E8AB7EFDB2EE15C718D5681A54D0CAC9091117E3A2B5DE, Exchange Server 2013 Cumulative Update 22, D4FAC21AEDB062744FADFF7950BA5F00F83D94721BCEDA0077852359F9F9F74C, Exchange Server 2013 Cumulative Update 21, E7A4056271FF35BB7D45D70AFDA226A8F4C7B0033246E7C7DD679414A48AAF9D, FDAA9379C910229A747170EDC4FF7E70235600F4CC30DAFA387858E4DB3CFC0C, 3134C249DF3F9A7B76AFFE7C257F01E3647BC63F680E0FD600CB78FEDE2E081B, 482BBBA9A39C936184FFE37FFB193793CDB162FB3B96AEE3A927E6B54B191C3A, Exchange Server 2016 Cumulative Update 11, 4F041E8C752E15F26AA536C3158641E8E80E23124689714F2E4836AA7D3C03CA, Exchange Server 2016 Cumulative Update 10, 8E31B64B8BD26A9F9A0D9454BAF220AACA9F4BC942BCF0B0ED5A2116DD212885, 8F13226F12A5B14586B43A80136D9973FE6FBB5724015E84D40B44087766E52E, 7661ECCFA103A177855C8AFFE8DDFEA0D8BDD949B6490976DC7A43CC0CD9078F, D0CCE0312FCEC4E639A18C9A2E34B736838DC741BAD188370CBFFFA68A81B192. The articles or blogs are under no circumstances intended to be used or considered as specific insurance or information security advice. Congratulations to the Top MSRC 2022 Q3 Security Researchers! CVE-2021-31206 is an unauthenticated RCE vulnerability targeting MS Exchange servers that enable attackers to compromise Internet-facing instances. Both bugs found by the NSA carry a CVSS score of 9.8 . XSPA Microsoft Exchange Server Spoofing Vulnerability CVE-2021-31209 8.1 - High - May 11, 2021 Microsoft Exchange Server Spoofing Vulnerability Microsoft Exchange Server Security Feature Bypass Vulnerability This vulnerability can be exploited to run arbitrary code in the target system. That is reflected in the high scores applied to the vulnerabilities, which range from 8.8 to 9.8 (critical). To get the standalone package for this update, go to theMicrosoft Update Catalogwebsite. This security update rollup resolves vulnerabilities in Microsoft Exchange Server. Once initial exploitation is successful actors are able to retrieve e-mail inventories from all users stored on the server. On April 13, 2021, CISA issued ED 21-02 Supplemental Direction V2, which directs federal departments and agencies to apply Microsoft's April 2021 Security Update that newly discloses and mitigates significant vulnerabilities affecting on-premises Exchange Server 2013, 2016, and 2019. Otherwise, register and sign in. 46 CVE-2020-17144: 502: Exec Code 2020-12-10: Best practices and the latest news on Microsoft FastTrack, The employee experience platform to help people thrive at work, Expand your Azure partner-to-partner network, Bringing IT Pros together through In-Person & Virtual events. The first breach of a Microsoft Exchange Server instance was observed by cybersecurity company Volexity on 6 January 2021. 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. Microsoft has released updates addressing Exchange Server versions 2010, 2013, 2016, and 2019. Microsoft Exchange Managed Availability services are also disabled to prevent mitigation regression. This may result in stale address book results in some scenarios and configurations. We installed November 2021 SU on our Exchange 2016/2019 servers. Deploy updates to affected Exchange Servers. These vulnerabilities affect on-premises Microsoft Exchange Server, including servers used by customers in Exchange Hybrid mode. Note:This issue does not occur if you install the update through Microsoft Update. Microsoft has pulled a security update for Exchange 2013 after problems emerged with the latest patch to the email server software just hours after its release. Add download domain to OWA virtual directory Step 5. Installing URL Rewrite version 2.1 on IIS versions 8.5 and lower may cause IIS and Exchange to become unstable. Go to https://aka.ms/ExchangeUpdateWizard and choose your currently running CU and your target CU to get directions for your environment. Exchange 2010 users can download the V2 release on their servers. Microsoft has released security updates for vulnerabilities found in: These updates are available for the following specific builds of Exchange Server: IMPORTANT:If manually installing security updates, youmustinstall .msp from elevated command prompt (see Known Issues in update KB article). If you've already registered, sign in. The issue occurs because the security update doesnt correctly stop certain Exchange-related services. Environments where the latest version of Exchange Server is any version before Exchange 2013, or environments where all Exchange servers have been removed, can use this script to address the vulnerability. The vulnerability exploits the Exchange Control Panel (ECP) via a Server-Side Request Forgery (SSRF). After installation of November SUs on your on-premises Exchange servers when in hybrid, you might see OWA redirection URL for hybrid users provide an incorrectly encoded URL, causing the redirect to fail. Please update your servers to resolve the vulnerability. Exchange Online customers are already protected and do not need to take any action. https://github.com/microsoft/CSS-Exchange/blob/main/Security/, https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2021-exchange-server-security-updates/ba-p/2175901, https://www.iis.net/downloads/microsoft/url-rewrite, https://www.microsoft.com/en-us/download/details.aspx?id=5747, https://www.microsoft.com/en-us/download/details.aspx?id=7435, Microsoft Safety Scanner Download Windows security, How to troubleshoot an error when you run the Microsoft Safety Scanner, Awareness and guidance related to OpenSSL 3.0 3.0.6 risk (CVE-2022-3786 and CVE-2202-3602), Microsoft Mitigates Vulnerability in Jupyter Notebooks for Azure Cosmos DB, Reflecting on Cybersecurity Awareness Month: At its Core, Cybersecurity is all about People. Select Language: Download DirectX End-User Runtime Web Installer DirectX End-User Runtime Web Installer Security Update For Exchange Server 2013 CU23 (KB5004778) System Requirements However, Outlook on the web and the Exchange Control Panel (ECP) mightstop working. This has now been corrected to mentionWindows Server Update Services (WSUS) instead (which is where the problem is. Their common vulnerability scoring system. Microsoft Exchange Server security vulnerabilities, exploits, metasploit modules, vulnerability statistics and list of versions . If . To avoid this issue, follow these steps to manually install this security update. Enable Download Domains Confirm Download Domains enabled Conclusion If something does not work properly after updates, see Repair failed installations of Exchange Cumulative and Security updates. Add download domain to external DNS Step 3. Microsoft Defender will continue to monitor and provide the latest security updates. 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