Is CVE-2021-42305 in the CISA KEV catalog?

No. CVE-2021-42305 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-42305?

CVE-2021-42305 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2021-42305?

CVE-2021-42305 has an EPSS score of 8.11% (94th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-42305?

Install KB5007409 for Microsoft Exchange Server 2013 Cumulative Update 23. Fixes are available for 5 affected products.

CVE & CISA-KEV Catalog

CVE-2021-42305

MEDIUMEPSS 94th pctl

6.5

CVSS v3

NVD

Description

Microsoft Exchange Server Spoofing Vulnerability

How to fix

Remediation Available

Microsoft Exchange Server 2013 Cumulative Update 23Microsoft

Install:KB5007409Microsoft

Microsoft Exchange Server 2016 Cumulative Update 21Microsoft

Install:KB5007409Microsoft

Microsoft Exchange Server 2016 Cumulative Update 22Microsoft

Install:KB5007409Microsoft

Microsoft Exchange Server 2019 Cumulative Update 10Microsoft

Install:KB5007409Microsoft

Microsoft Exchange Server 2019 Cumulative Update 11Microsoft

Install:KB5007409Microsoft

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Exploit Intelligence

8.11%probability of exploitation in 30 days

94thpercentile

High risk: more likely to be exploited than 94% of all known CVEs.

References

Patch1

portal.msrc.microsoft.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.