Security readout for executives and security teams
Plain-English summary
CVE-2021-31960 is a Windows Bind Filter Driver information disclosure flaw. It matters because a local, low-privileged user could access sensitive information from affected Windows systems. The impact is confidentiality only; the sources do not show remote takeover, data modification, or service disruption.
Executive priority
Handle in normal patch governance with moderate priority. Escalate where affected systems host sensitive data or allow many local users. The available evidence supports remediation, but not emergency response for active exploitation.
Technical view
The CVSS 3.1 vector is AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, scoring 5.5. Exploitation requires local access and low privileges, needs no user interaction, and can disclose high-value information. Microsoft is the affected vendor; no CWE is provided in the bundle.
Likely exposure
Exposure is most likely on unpatched Windows 10 Version 21H1, 2004, 20H2, and Windows Server version 2004 or 20H2 systems matching the listed builds. Internet exposure alone is not the main issue because the vector is local.
Exploitation context
The bundle does not show CISA KEV listing or cited active exploitation. CVSS exploit maturity is marked unproven. Treat this as a local post-access confidentiality risk that could matter more on shared workstations, servers, or environments with weak account controls.
Researcher notes
Focus assessment on local privilege boundaries and information disclosure impact. The source bundle gives affected product/build data and CVSS details, but not root cause detail, exploit primitives, or named mitigations beyond Microsoft's advisory path.
Mitigation direction
- Apply Microsoft's official guidance for CVE-2021-31960 through MSRC and Windows Update.
- Prioritize affected servers and shared Windows endpoints before lower-risk single-user systems.
- Reduce unnecessary local user access on affected Windows hosts.
- Check vendor guidance if specific update applicability is unclear.
Validation and detection
- Inventory Windows 10 21H1, 2004, 20H2, and Windows Server 2004 or 20H2 systems.
- Compare installed build and update status against the MSRC advisory for CVE-2021-31960.
- Confirm the system is no longer reporting the affected build state.
- Review whether low-privileged local accounts exist on sensitive affected hosts.
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-2021-31960 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
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31960CVE reference · x_refsource_MISC
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.