Microsoft Exchange Server Security Feature Bypass 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
- Metrics
- CVSS:3.1 6.6 / 5.8Base score metrics: 6.6 / Temporal score metrics: 5.8
Attack Vector
Network
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Exploit Code Maturity
Unproven
Remediation Level
Official Fix
Report Confidence
Confirmed
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
Security Updates
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.
- 15.02.0792.015
- 15.01.2176.014
- 15.01.2242.010
- 15.02.0858.012
- 15.00.1497.018
Disclaimer
Revisions
Added an FAQ. This is an information change only.
Information published.