Microsoft Exchange Server Security Feature Bypass Vulnerability

Security Vulnerability

Released: May 11, 2021

Last updated: Oct 26, 2023

Assigning CNA
Microsoft
CVE.org link
CVE-2021-31207
Impact
Defense in Depth
Max Severity
Moderate
Vector String
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Please see Common Vulnerability Scoring System for more information on the definition of these metrics.

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed
Yes
Exploited
No
Exploitability assessment
Exploitation Less Likely

FAQ

Was this vulnerability found in the 2021 Pwn2Own contest?

Yes, this was one of the Exchange Server vulnerabilities found in the 2021 Pwn2Own contest.

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?

Successful exploitation of this vulnerability requires an attacker to take additional actions prior to exploitation to prepare the target environment.

Acknowledgements

  • Orange Tsai(@orange_8361) from DEVCORE Research Team working with Trend Micro Zero Day Initiative
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

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