Security readout for executives and security teams
Plain-English summary
A local attacker with low privileges could use this Windows driver flaw to gain higher privileges. It is not a remote entry point, but it can turn an initial foothold into full system control. CISA KEV status indicates recognized in-the-wild exploitation.
Executive priority
Treat this as a high-priority patch validation item because it is known exploited and can convert limited access into full system compromise.
Technical view
CVE-2021-36955 is a Windows Common Log File System driver elevation-of-privilege vulnerability, CVSS 7.8. The vector is local, low complexity, low privilege, no user interaction, with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely on affected Windows 7, 8.1, 10, and Windows Server 2008, 2016, 2019, or 2022 systems that remain unpatched or unsupported.
Exploitation context
CISA lists this CVE in its Known Exploited Vulnerabilities catalog. The provided sources do not describe exploit volume, attacker groups, or technical exploitation details.
Researcher notes
The source bundle confirms affected products, CVSS vector, Microsoft advisory, and KEV status. It does not provide root-cause details, exploit prerequisites beyond local low-privilege access, or detection logic.
Mitigation direction
- Apply Microsoft security updates for affected Windows versions per MSRC guidance.
- Prioritize internet-facing, shared, and high-value Windows systems for verification.
- Confirm legacy Windows support status and use Microsoft-supported updates or isolation guidance.
- Restrict local administrative access and monitor privileged account use.
Validation and detection
- Inventory Windows builds against the affected product list in the CVE bundle.
- Verify installed Microsoft security updates cover CVE-2021-36955.
- Check vulnerability scanner results for remaining affected hosts.
- Review endpoint telemetry for unexpected privilege escalation 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.
Privilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-36955 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
- 7.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/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
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:H/A:H/E:F/RL:O/RC:C1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36955CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36955CVE reference · 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.