What We Do
How we do it
Resources
Company
ABOUT ESENTIRE
About Us
eSentire is The Authority in Managed Detection and Response Services, protecting the critical data and applications of 2000+ organizations in 80+ countries from known and unknown cyber threats. Founded in 2001, the company’s mission is to hunt, investigate and stop cyber threats before they become business disrupting events.
Read about how we got here
Leadership Work at eSentire
LATEST PRESS RELEASE
Mar 20, 2023
Exertis and eSentire Partner to Deliver 24/7 Multi-Signal MDR, Digital Forensics & IR Services and Exposure Management to Organisations Across the UK, Ireland, and Europe
Basingstoke, UK– 20 March, 2023. Leading technology distributor, Exertis, announced today that it has bolstered its cybersecurity services, adding eSentire, the Authority in Managed Detection and Response (MDR), to its Enterprise portfolio of offerings. eSentire’s award-winning, 24/7 multi-signal MDR, Digital Forensics & Incident Response (IR), and Exposure Management services will be available…
Read More
Partners
PARTNER PROGRAM
e3 Ecosystem
We provide sophisticated cybersecurity solutions for Managed Security Service Providers (MSSPs), Managed Service Providers (MSPs), and Value-Added Resellers (VARs). Find out why you should partner with eSentire, the Authority in Managed Detection and Response, today.
Learn more
ECOSYSTEM PARTNER RESOURCES
Apply to become an e3 ecosystem partner with eSentire, the Authority in Managed Detection and Response.
Login to the Partner Portal for resources and content for current partners.
Search
Resources
Security advisories — Mar 08, 2021

Update 2: Multiple 0-Day Exploits Targeting on Premise Exchange Versions

2 minutes read
Speak With A Security Expert Now

THE THREAT

In response to the ongoing exploitation of recently disclosed Microsoft Exchange server zero-day vulnerabilities, Microsoft has released new mitigations for organizations that are currently unable to apply the required security patches. Importantly, Microsoft has also released the Microsoft Support Emergency Response Tool (MSERT). The MSERT tool can be used to detect and remediate known threats abusing these vulnerabilities.

Organizations are strongly recommended to ensure that security patches or mitigations are deployed to prevent exploitation. The MSERT tool should be used to help identify potentially malicious actions that may have occurred prior to patch or mitigation deployment.

What we’re doing about it

What you should do about it

Additional information

Confirmed vulnerable on-premises Microsoft Exchange Servers:

Exploited Vulnerabilities:

Microsoft has provided mitigations to defend against attacks exploiting all of the previously stated vulnerabilities. It should be noted that applying the mitigation actions will result in functionality degradation in Exchange servers. The functionality impact of each mitigation action is outline in detail in the official release. Microsoft has released a free Nmap script to scan for CVE-2021-26855.

References:

[1] https://msrc.microsoft.com/update-guide/releaseNote/2021-Mar

[2] https://msrc-blog.microsoft.com/2021/03/05/microsoft-exchange-server-vulnerabilities-mitigations-march-2021/

[3] https://docs.microsoft.com/en-us/windows/security/threat-protection/intelligence/safety-scanner-download

[4] https://github.com/microsoft/CSS-Exchange/blob/main/Security/http-vuln-cve2021-26855.nse

View Most Recent Blogs