Security readout for executives and security teams
Plain-English summary
CVE-2021-31973 is a Microsoft Windows elevation-of-privilege issue in GPSVC. It does not appear to be a remote entry point; an attacker already on a vulnerable Windows system with low privileges could potentially gain higher privileges. Microsoft rated it high severity with full confidentiality, integrity, and availability impact.
Executive priority
Treat as high priority for patch governance, especially on servers and privileged-user workstations. It is not evidenced as actively exploited here, but successful abuse could turn a limited local compromise into broad system control.
Technical view
The source bundle lists CVSS 3.1 score 7.8 with AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Affected platforms include multiple Windows 10 releases, Windows 7/8.1, Windows Server 2008 through 2019, and Server Core variants. Microsoft has an advisory, and the temporal vector indicates an official remediation exists.
Likely exposure
Exposure is most likely on older or unpatched Windows endpoints and servers matching the listed affected versions and builds. Because the vector is local with low privileges required, this is mainly a post-compromise or insider-risk escalation path, not a standalone internet-facing exposure.
Exploitation context
The bundle does not show CISA KEV listing or cited active exploitation. The CVSS temporal vector marks exploit maturity as unproven. Treat it as a serious privilege-escalation risk, especially where attackers may already have footholds on Windows hosts.
Researcher notes
Do not assume remote exploitability from this bundle. The key constraints are local access, low privileges, no user interaction, unchanged scope, and high CIA impact. Evidence is limited to the CVE metadata, affected CPEs, KEV=false, and Microsoft advisory reference.
Mitigation direction
- Apply Microsoft guidance and security updates for CVE-2021-31973.
- Prioritize patching affected Windows servers and high-value endpoints.
- Check Microsoft guidance for systems without an applicable update path.
- Reduce unnecessary local user access on affected Windows systems.
Validation and detection
- Inventory Windows versions and builds against the affected product list.
- Confirm the Microsoft advisory remediation is installed or otherwise addressed.
- Prioritize validation on servers, Server Core, and shared workstations.
- Track exceptions where patch status cannot be confirmed.
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-2021-31973 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
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H/I:H/A:H/E:U/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:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31973CVE 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.