Critical CVSS 5.5 EPSS 0.99512 2020-08 archive

Executive Summary

An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller, using the Netlogon Remote Protocol ( MS-NRPC ). An attacker who successfully exploited the vulnerability could run a specially crafted application on a device on the network. To exploit the vulnerability, an unauthenticated attacker would be required to use MS-NRPC to connect to a domain controller to obtain domain administrator access. Microsoft is addressing the vulnerability in a phased two-part rollout. These updates address the vulnerability by modifying how Netlogon handles the usage of Netlogon secure channels. For guidelines on how to manage the changes required for this vulnerability and more information on the phased rollout, see How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472 (updated September 28, 2020). When the second phase of Windows updates become available in Q1 2021, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this advisory. See Microsoft Technical Security Notifications .

Overview

5.5
CVSS MEDIUM
Critical
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
Category Elevation of Privilege
Released Aug 11 2020
Last Updated Aug 11 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.99512 — 0.99939 percentile
NVD CVSS 5.5 MEDIUM — differs from MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 9.0

EPSS Score

0.99512
probability of exploitation in the next 30 days
0.99939 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

8 affected products
Product KB Article Severity Impact Restart Required
Windows Server 2008 R2 for x64-based Systems Service Pack 1 4601347 (Monthly Rollup) 4601363 (Security Only) Critical Elevation of Privilege 4598279 Base: 10.0 Temporal: 9.0 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4601347 4601363 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4601347 (Monthly Rollup) 4601363 (Security Only) Critical Elevation of Privilege 4598279 Base: 10.0 Temporal: 9.0 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4601347 4601363 Windows Server 2012 4601348 (Monthly Rollup) 4601357 (Security Only) Critical Elevation of Privilege 4598278 Base: 10.0 Temporal: 9.0 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4601348 4601357 Windows Server 2012 (Server Core installation) 4601348 (Monthly Rollup) 4601357 (Security Only) Critical Elevation of Privilege 4598278 Base: 10.0 Temporal: 9.0 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4601348 4601357 Windows Server 2012 R2 4601384 (Monthly Rollup) 4601349 (Security Only) Critical Elevation of Privilege 4598285 Base: 10.0 Temporal: 9.0 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4601384 4601349 Windows Server 2012 R2 (Server Core installation) 4601384 (Monthly Rollup) 4601349 (Security Only) Critical Elevation of Privilege 4598285 Base: 10.0 Temporal: 9.0 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4601384 4601349 Windows Server 2016 4601318 (Security Update) Critical Elevation of Privilege Yes
Windows Server 2016 (Server Core installation) 4601318 (Security Update) Critical Elevation of Privilege Yes
Windows Server 2019 4601345 (Security Update) Critical Elevation of Privilege Yes
Windows Server 2019 (Server Core installation) 4601345 (Security Update) Critical Elevation of Privilege Yes
Windows Server, version 1903 (Server Core installation) 4565351 (Security Update) Critical Elevation of Privilege Yes
Windows Server, version 1909 (Server Core installation) 4601315 (Security Update) Critical Elevation of Privilege Yes
Windows Server, version 2004 (Server Core installation) 4601319 (Security Update) Critical Elevation of Privilege Yes
Windows Server, version 20H2 (Server Core Installation) 4601319 (Security Update) Critical Elevation of Privilege Yes

Patches

5 patches
Article Type Restart
4601318 Security Update Yes
4601345 Security Update Yes
4565351 Security Update Yes
4601315 Security Update Yes
4601319 Security Update Yes

Known Exploits

Acknowledgments

Tom Tervoort of Secura, Zhiniang Peng (@edwardzpeng) & Xuefeng Li (@lxf02942370)