Security readout for executives and security teams
Plain-English summary
CVE-2021-36942 is a high-severity Windows LSA spoofing vulnerability affecting multiple Windows Server releases. A network attacker may exploit it without credentials or user interaction, potentially exposing sensitive information. CISA lists the vulnerability as known exploited, making remediation urgent where affected systems remain deployed.
Executive priority
Treat this as an urgent patching priority because exploitation is documented and attacks require neither credentials nor user interaction. Confirm coverage across legacy and Server Core installations, then track exceptions until resolved or isolated.
Technical view
The CVSS 3.1 score is 7.5. The vector indicates network access, low complexity, no required privileges, and no user interaction. The documented impact is high confidentiality loss, with no rated integrity or availability impact. Scope remains unchanged.
Likely exposure
Potentially exposed assets include the listed Windows Server 2008 SP2, 2008 R2 SP1, 2012, 2012 R2, 2016, 2019, version 2004, and 20H2 systems, including Server Core variants. Actual exposure depends on installed security updates and network reachability.
Exploitation context
CISA's Known Exploited Vulnerabilities listing supports active exploitation in the wild. The source bundle does not describe observed campaigns, affected organizations, exploitation frequency, or attacker objectives, so those details remain unknown.
Researcher notes
Evidence supports unauthenticated, low-complexity network exploitation with confidentiality impact. It does not establish integrity or availability impact. The supplied sources provide no campaign details, indicators, exploit mechanics, or alternative mitigation sufficient to replace Microsoft's update.
Mitigation direction
- Apply Microsoft's security update for CVE-2021-36942 to every affected, supported Windows Server system.
- Prioritize network-reachable servers and systems handling credentials or sensitive information.
- Consult current Microsoft guidance for release-specific update requirements and any prerequisites.
- Restrict unnecessary network access to unremediated affected servers until updates are verified.
Validation and detection
- Inventory servers against every product and version listed in the Microsoft advisory.
- Confirm the applicable Microsoft security update is installed successfully on each affected server.
- Use authenticated vulnerability scanning or endpoint inventory to identify missing updates.
- Review security monitoring for suspicious activity involving affected systems; available sources provide no specific indicators.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-36942 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:O/RC:C3.93.6microsoftVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2021-36942 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2021-11-03T00:00:00.000Z: CVE-2021-36942 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- Windows LSA Spoofing VulnerabilityCVE reference, microsoft · vendor-advisory, patch
- VU#405600CVE reference, CVE · third-party-advisory, x_refsource_CERT-VN
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942CVE reference, CVE · x_refsource_MISC, x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36942CVE reference, CISA-ADP · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.