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Fencer Intel
medium 6.5

CVE-2021-33745 json

Windows DNS Server Denial of Service Vulnerability

published 5y ago modified 2mo ago also EUVD-2021-20422

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.9%
EPSS 2.9% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

Windows DNS Server Denial of Service Vulnerability

Patch / fix

  • Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.25661
  • Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation) 6.1.7601.25661
  • Microsoft Windows Server 2008 Service Pack 2 6.0.6003.21167
  • Microsoft Windows Server 2008 Service Pack 2 (Server Core installation) 6.0.6003.21167
  • Microsoft Windows Server 2012 6.2.9200.23409
  • Microsoft Windows Server 2012 (Server Core installation) 6.2.9200.23409
  • Microsoft Windows Server 2012 R2 6.3.9600.20069
  • Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.20069
  • Microsoft Windows Server 2016 10.0.14393.4530
  • Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.4530
  • Microsoft Windows Server 2019 10.0.17763.2061
  • Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.2061
  • Microsoft Windows Server version 2004 10.0.19041.1110
  • Microsoft Windows Server version 20H2 10.0.19042.1110

Is CVE-2021-33745 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

2.87% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P

Affected products

  • Microsoft Windows Server 2008 R2 Service Pack 1
  • Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation)
  • Microsoft Windows Server 2008 Service Pack 2
  • Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)
  • Microsoft Windows Server 2012
  • Microsoft Windows Server 2012 (Server Core installation)
  • Microsoft Windows Server 2012 R2
  • Microsoft Windows Server 2012 R2 (Server Core installation)
  • Microsoft Windows Server 2016
  • Microsoft Windows Server 2016 (Server Core installation)
  • Microsoft Windows Server 2019
  • Microsoft Windows Server 2019 (Server Core installation)
  • Microsoft Windows Server version 2004
  • Microsoft Windows Server version 20H2

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.