Microsoft · Security update · April 13, 2021

KB5001779: April 2021 security update

KB5001779, released April 13, 2021, fixes 7 CVEs across 5 products. 3 of them are being exploited (CVE-2021-34473); 3 on CISA KEV. Patch Radar priority: Patch now. The product is no longer supported.

Patch now3 on CISA KEVKnown ransomware use2 publicly disclosedUnsupported product
CVEs closed
7
5 rated Critical
Exploited
3
CVE-2021-34473
Exploitation more likely
4
Vendor assessment
Highest EPSS
1.0000
99th percentile

Priority of the 7 CVEs

Patch now 3 Urgent 4 High 0 Routine 0

Applies to

CVEs this fix closes

PriorityCVEComponentImpactCVSSEPSSExploitation
Patch now CVE-2021-34473 Microsoft Exchange Server Remote Code Execution 9.1 1.0000 KEVRansomwareDisclosedExploited
Patch now CVE-2021-34523 Microsoft Exchange Server Elevation of Privilege 9.0 0.9999 KEVRansomwareDisclosedExploited
Patch now CVE-2021-33766 Microsoft Exchange Server Information Disclosure 7.3 0.9818 KEVExploited
Urgent CVE-2021-28482 Microsoft Exchange Server Remote Code Execution 8.8 0.8321 More likely
Urgent CVE-2021-28480 Microsoft Exchange Server Remote Code Execution 9.8 0.7123 More likely
Urgent CVE-2021-28481 Microsoft Exchange Server Remote Code Execution 9.8 0.3624 More likely
Urgent CVE-2021-28483 Microsoft Exchange Server Remote Code Execution 9.0 0.0120 More likely
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