Security readout for executives and security teams
Plain-English summary
This Windows vulnerability could let a locally authenticated user read sensitive information from affected systems. It is not described as remotely exploitable and the supplied sources do not show active exploitation. Treat it as a normal security update priority, with higher urgency for shared servers, legacy Windows, and systems handling sensitive data.
Executive priority
Address through standard patch governance, not emergency response, unless affected systems are sensitive, shared, or already exposed to untrusted local users. The business risk is confidentiality loss after local access, not remote takeover based on supplied evidence.
Technical view
CVE-2021-1676 is an information disclosure issue in the Windows NT Lan Manager Datagram Receiver Driver. CVSS 3.1 is 5.5: local attack vector, low complexity, low privileges, no user interaction, unchanged scope, high confidentiality impact, and no integrity or availability impact.
Likely exposure
Exposure is limited to affected Windows client and server versions listed by Microsoft, including Windows 7, 8.1, multiple Windows 10 releases, and Windows Server 2008 through 2019 variants. An attacker needs local low-privileged access first.
Exploitation context
The source bundle marks KEV as false and CVSS exploit maturity as unproven. No cited source in the bundle supports active exploitation. Public details are limited, so assume exploitation requires local access but do not infer specific techniques.
Researcher notes
Focus validation on OS version, patch state, and local privilege boundaries. The bundle does not provide exploit details, root cause depth, or package-specific remediation identifiers beyond Microsoft advisory references and CVSS remediation level indicating an official fix.
Mitigation direction
- Check Microsoft guidance for CVE-2021-1676 and apply applicable security updates.
- Prioritize shared servers, legacy Windows systems, and sensitive-data endpoints.
- Remove or isolate unsupported Windows versions where updates are unavailable.
- Restrict local interactive access to systems handling sensitive information.
Validation and detection
- Inventory Windows versions against the affected product list.
- Confirm CVE-2021-1676 is covered in endpoint patch records.
- Verify legacy Windows assets have compensating controls if unpatched.
- Review local account access on affected servers and workstations.
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-2021-1676 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
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/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.
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- Windows NT Lan Manager Datagram Receiver Driver Information Disclosure VulnerabilityCVE reference · vendor-advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1676CVE reference · x_refsource_MISC, x_transferred
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.