Security readout for executives and security teams
Plain-English summary
CVE-2021-1670 is a Microsoft Windows information disclosure issue in the Projected File System filter driver. A local, low-privileged attacker could potentially expose sensitive information, but the sources do not indicate remote compromise, data modification, service disruption, or active exploitation.
Executive priority
Treat this as a routine but real patch-management item. It is not currently supported as actively exploited by the provided sources, but confidentiality impact is high on affected systems and remediation is available.
Technical view
The CVSS 3.1 vector is AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N with score 5.5. This indicates local access, low attack complexity, required low privileges, no user interaction, and confidentiality impact only. Microsoft lists official remediation availability.
Likely exposure
Exposure appears limited to affected Microsoft Windows 10 Version 20H2, Windows Server version 20H2, Windows 10 Version 2004, and Windows Server version 2004 systems listed in the source bundle. Confirm exact build applicability against MSRC guidance.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. The CVSS exploit maturity value is unproven. Any abuse would require local access with low privileges, so shared workstations, terminal servers, and systems allowing untrusted code are more relevant.
Researcher notes
The evidence is sparse: title, product list, CVSS vector, and Microsoft advisory links. No CWE, technical root cause detail, exploitation narrative, or workaround is included. Avoid asserting affected builds beyond the source bundle and MSRC confirmation.
Mitigation direction
- Apply Microsoft security updates for CVE-2021-1670 to affected Windows systems.
- Review MSRC guidance for exact affected builds and update status.
- Prioritize shared or multi-user Windows hosts where local access is common.
- Restrict local interactive access and code execution to trusted users.
- Monitor vendor advisories for any updated remediation or exploit information.
Validation and detection
- Inventory assets running the Windows versions listed in the source bundle.
- Confirm applicable Microsoft security updates for CVE-2021-1670 are installed.
- Check vulnerability scanner results against MSRC product applicability.
- Verify shared Windows hosts have limited local user access.
- Document exceptions where affected systems cannot be updated promptly.
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-2021-1670 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 Projected File System FS Filter Driver Information Disclosure VulnerabilityCVE reference · vendor-advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1670CVE 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.