CVE-2021-26855 Report - Details, Severity, & Advisories
Twingate Team
•
May 31, 2024
What is CVE-2021-26855?
CVE-2021-26855 is a critical vulnerability affecting Microsoft Exchange Server, with a severity score of 9.8 out of 10. Systems running vulnerable versions of Microsoft Exchange Server, including 2013, 2016, and 2019, are at risk. It is essential for organizations to address this vulnerability to protect their systems and data from potential exploitation.
Who is impacted by CVE-2021-26855?
Specifically, it impacts Exchange 2013 versions below 15.00.1497.012, Exchange 2016 CU18 below 15.01.2106.013, Exchange 2016 CU19 below 15.01.2176.009, Exchange 2019 CU7 below 15.02.0721.013, and Exchange 2019 CU8 below 15.02.0792.010. This critical vulnerability allows attackers to bypass authentication and impersonate an admin, potentially leading to remote code execution on the affected servers.
What should I do if I’m affected?
If your organization is affected by the CVE-2021-26855 vulnerability, it's crucial to take immediate action to protect your systems and data. Here are some simplified steps to follow:
Update your Microsoft Exchange Server to the latest version to patch the vulnerability.
Regularly monitor and review logs for suspicious activity.
Implement strong access controls and authentication mechanisms.
Keep software up-to-date and follow security best practices.
Is this in CISA’s Known Exploited Vulnerabilities Catalog?
Yes, the CVE-2021-26855 vulnerability, also known as Microsoft Exchange Server Remote Code Execution Vulnerability, is listed in CISA's Known Exploited Vulnerabilities Catalog. It was added on November 3, 2021, with a due date of April 16, 2021.
Weakness Enumeration
The weakness enumeration for this vulnerability is categorized as CWE-918, which is a Server-Side Request Forgery (SSRF) issue affecting Microsoft Exchange Server.
Learn More
For a comprehensive understanding of this vulnerability, including its description, severity, technical details, and known affected software configurations, refer to the NVD page or the resources listed below.
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CVE-2021-26855 Report - Details, Severity, & Advisories
Twingate Team
•
May 31, 2024
What is CVE-2021-26855?
CVE-2021-26855 is a critical vulnerability affecting Microsoft Exchange Server, with a severity score of 9.8 out of 10. Systems running vulnerable versions of Microsoft Exchange Server, including 2013, 2016, and 2019, are at risk. It is essential for organizations to address this vulnerability to protect their systems and data from potential exploitation.
Who is impacted by CVE-2021-26855?
Specifically, it impacts Exchange 2013 versions below 15.00.1497.012, Exchange 2016 CU18 below 15.01.2106.013, Exchange 2016 CU19 below 15.01.2176.009, Exchange 2019 CU7 below 15.02.0721.013, and Exchange 2019 CU8 below 15.02.0792.010. This critical vulnerability allows attackers to bypass authentication and impersonate an admin, potentially leading to remote code execution on the affected servers.
What should I do if I’m affected?
If your organization is affected by the CVE-2021-26855 vulnerability, it's crucial to take immediate action to protect your systems and data. Here are some simplified steps to follow:
Update your Microsoft Exchange Server to the latest version to patch the vulnerability.
Regularly monitor and review logs for suspicious activity.
Implement strong access controls and authentication mechanisms.
Keep software up-to-date and follow security best practices.
Is this in CISA’s Known Exploited Vulnerabilities Catalog?
Yes, the CVE-2021-26855 vulnerability, also known as Microsoft Exchange Server Remote Code Execution Vulnerability, is listed in CISA's Known Exploited Vulnerabilities Catalog. It was added on November 3, 2021, with a due date of April 16, 2021.
Weakness Enumeration
The weakness enumeration for this vulnerability is categorized as CWE-918, which is a Server-Side Request Forgery (SSRF) issue affecting Microsoft Exchange Server.
Learn More
For a comprehensive understanding of this vulnerability, including its description, severity, technical details, and known affected software configurations, refer to the NVD page or the resources listed below.
Rapidly implement a modern Zero Trust network that is more secure and maintainable than VPNs.
CVE-2021-26855 Report - Details, Severity, & Advisories
Twingate Team
•
May 31, 2024
What is CVE-2021-26855?
CVE-2021-26855 is a critical vulnerability affecting Microsoft Exchange Server, with a severity score of 9.8 out of 10. Systems running vulnerable versions of Microsoft Exchange Server, including 2013, 2016, and 2019, are at risk. It is essential for organizations to address this vulnerability to protect their systems and data from potential exploitation.
Who is impacted by CVE-2021-26855?
Specifically, it impacts Exchange 2013 versions below 15.00.1497.012, Exchange 2016 CU18 below 15.01.2106.013, Exchange 2016 CU19 below 15.01.2176.009, Exchange 2019 CU7 below 15.02.0721.013, and Exchange 2019 CU8 below 15.02.0792.010. This critical vulnerability allows attackers to bypass authentication and impersonate an admin, potentially leading to remote code execution on the affected servers.
What should I do if I’m affected?
If your organization is affected by the CVE-2021-26855 vulnerability, it's crucial to take immediate action to protect your systems and data. Here are some simplified steps to follow:
Update your Microsoft Exchange Server to the latest version to patch the vulnerability.
Regularly monitor and review logs for suspicious activity.
Implement strong access controls and authentication mechanisms.
Keep software up-to-date and follow security best practices.
Is this in CISA’s Known Exploited Vulnerabilities Catalog?
Yes, the CVE-2021-26855 vulnerability, also known as Microsoft Exchange Server Remote Code Execution Vulnerability, is listed in CISA's Known Exploited Vulnerabilities Catalog. It was added on November 3, 2021, with a due date of April 16, 2021.
Weakness Enumeration
The weakness enumeration for this vulnerability is categorized as CWE-918, which is a Server-Side Request Forgery (SSRF) issue affecting Microsoft Exchange Server.
Learn More
For a comprehensive understanding of this vulnerability, including its description, severity, technical details, and known affected software configurations, refer to the NVD page or the resources listed below.
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