CVE-2021-42305
Microsoft Exchange Server Spoofing Vulnerability
Microsoft Exchange Server Spoofing Vulnerability
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Exchange Server Spoofing Vulnerability
Microsoft Exchange Server Spoofing Vulnerability
- Record
CVE-2021-42305- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C - Updated
- 2026-11-02
EUVDEUVD-2021-29280
Microsoft Exchange Server Spoofing Vulnerability
- Record
EUVD-2021-29280- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-ch43-44fr-3cm6
Microsoft Exchange Server Spoofing Vulnerability This CVE ID is unique from CVE-2021-41349.
Microsoft Exchange Server Spoofing Vulnerability This CVE ID is unique from CVE-2021-41349.
- Record
GHSA-ch43-44fr-3cm6- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
NVD
Microsoft Exchange Server Spoofing Vulnerability
- Record
CVE-2021-42305- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-42305 is a medium vulnerability (CVSS 6.5) in Microsoft Exchange Server, published November 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 7.87%, the 94th percentile. No source names a fixed version.