CVE-2021-42278KEV · OVERDUE

Microsoft Active Directory Domain Services Privilege Escalation Vulnerability

High · published November 10, 2021

Patch now

Confirmed exploited, and the score agrees

CVSS calls it high at 7.5. It is confirmed in active exploitation. It sits in the 99.5th percentile for exploit probability.

1636
days past CISA
deadline
CVSS v3.1
7.5
EPSS
73%
Percentile
99.5
In the wild
Confirmed
What it is

🚨 An Active Directory vulnerability could let an attacker elevate privileges like a party crasher suddenly being handed the keys to the VIP lounge! ⚡ Think of Active Directory as a big corporate office — if someone sneaks past reception without a badge, they could easily wander into restricted areas and access sensitive files, putting the entire company at risk. If exploited, this vulnerability allows a malicious user to elevate their privileges, gaining access to restricted resources and potentially compromising the entire network. This could lead to data breaches, unauthorized changes to critical systems, and a significant loss of trust with clients and partners. It's a high-stakes game that could have devastating consequences for your organization.

Put simply

Think of Active Directory as a big corporate office — if someone sneaks past reception without a badge, they could easily wander into restricted areas and access sensitive files, putting the entire company at risk. This Elevation of Privilege vulnerability in Active Directory Domain Services allows an attacker to gain higher privileges than intended, enabling them to perform unauthorized actions within the network. Essentially, it exploits flaws in how permissions are checked, letting attackers bypass necessary security measures.

What to do

If exploited, this vulnerability allows a malicious user to elevate their privileges, gaining access to restricted resources and potentially compromising the entire network. This could lead to data breaches, unauthorized changes to critical systems, and a significant loss of trust with clients and partners. It's a high-stakes game that could have devastating consequences for your organization. To remediate this vulnerability, make sure to apply the latest security updates from Microsoft immediately. Review your Active Directory permissions and user roles to ensure they adhere to the principle of least privilege. Implement monitoring for any unusual activity on your Active Directory domains. You've got this! Stay vigilant, patch promptly, and keep your defenses strong! 🛡️

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.73297 · 99.5th percentile
Published
2021-11-10T06:19Z
KEV added
2022-04-11 · due 2022-05-02
Affected products (9)
ProductVersionsFixed in
microsoft/windows_server_2004< 10.0.19041.134810.0.19041.1348
microsoft/windows_server_2008all versions—
microsoft/windows_server_2008all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2016< 10.0.14393.477010.0.14393.4770
microsoft/windows_server_2019< 10.0.17763.230010.0.17763.2300
microsoft/windows_server_2022< 10.0.20348.35010.0.20348.350
microsoft/windows_server_20h2< 10.0.19042.134810.0.19042.1348
References (3)
EPSS history
Timeline
  • 11 APR 00:00Z
    Added to CISA KEV — remediate by May 2
    kev
  • 10 NOV 00:47Z
    Active Directory Domain Services Elevation of Privilege Vulnerability
    cvelistv5