CVE-2021-34442: Windows DNS Server Remote Code Execution Vulnerability

Overview

Severity
High (CVSS 8.8)
CVSS Vector
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Remote Code Execution
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2021-Jul
Released
2021-07-13
Last Updated
2021-09-14
EPSS Score
6.94% (percentile: 91.4%)

FAQ

If my server is not configured to be a DNS server, it is vulnerable? No, this vulnerability is only exploitable if the server is configured to be a DNS server.

Affected Products (16)

Windows

  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server, version 2004 (Server Core installation)
  • Windows Server, version 20H2 (Server Core Installation)
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

ESU

  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)

Security Updates (11)

Acknowledgments

<a href="https://twitter.com/guhe120">Yuki Chen</a>, ZhiyiZhang from Codesafe Team of Legendsec at Qi'anxin Group

Revision History

  • 2021-07-13: Information published.
  • 2021-09-14: The following revisions have been made: 1) In the Security Updates table, corrected the impact entries to Remote Code Execution. 2) The CVSS scores have been updated. These are informational changes only. Customers who have successfully installed the update do not need to take any further action.