Security readout for executives and security teams
Plain-English summary
This is a Microsoft Windows denial-of-service issue in Desktop Bridge. A local, low-privileged user could affect system availability. The provided data does not show data theft, privilege escalation, or remote compromise. Treat it as a patch-management item for affected Windows 10 and Windows Server releases.
Executive priority
Handle through normal vulnerability management unless critical systems remain unpatched. Business urgency is moderate because impact is availability-only and local, with no cited active exploitation, but affected shared systems can still disrupt operations.
Technical view
CVE-2021-31185 is rated CVSS 5.5 with local attack vector, low complexity, low privileges required, no user interaction, unchanged scope, and high availability impact only. Affected products listed are Windows 10 2004/20H2 and Windows Server 2004/20H2.
Likely exposure
Exposure is likely limited to assets running the listed Windows 10 or Windows Server 2004/20H2 versions/builds. The bundle does not identify cloud services, third-party products, or broader Windows versions as affected.
Exploitation context
The source bundle says KEV is false and CVSS exploit maturity is unproven. Active exploitation is not supported by the provided evidence. Exploitation requires local access with low privileges, which lowers internet-facing risk but matters on shared endpoints and servers.
Researcher notes
Evidence is sparse: the public description only names Windows Desktop Bridge denial of service. No CWE, root-cause detail, exploit technique, or specific workaround is provided in the bundle. Do not infer affected products beyond the listed Microsoft releases.
Mitigation direction
- Review Microsoft guidance for CVE-2021-31185 and apply the official fix.
- Prioritize affected shared workstations, jump hosts, and multi-user servers.
- Remove unsupported or unpatched Windows 10/Server 2004 and 20H2 assets from production.
- Use endpoint management reporting to track remediation completion.
Validation and detection
- Inventory Windows 10 and Windows Server assets for 2004 and 20H2 releases.
- Compare installed build and patch status against Microsoft’s CVE advisory.
- Confirm the vulnerability is absent from vulnerability scanner results after remediation.
- Document any affected systems that cannot be patched and their compensating controls.
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-2021-31185 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:N/I:N/A:H/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:N/I:N/A:H/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:N/I:N/A:H/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-2021-31185CVE 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.