Security readout for executives and security teams
Plain-English summary
This is a Windows local privilege escalation issue in WalletService. An attacker already able to run low-privileged code on an affected Windows 10 system could potentially gain higher privileges. It is not remotely exploitable by itself, but it can raise the impact of malware, phishing, or an initial endpoint compromise.
Executive priority
Patch through normal high-priority endpoint remediation workflows. Escalate where affected systems are internet-facing jump hosts, shared endpoints, or privileged administration workstations because local privilege escalation can turn a limited foothold into full host control.
Technical view
CVE-2021-1687 affects Microsoft Windows WalletService on listed Windows 10 versions. The CVSS 3.1 score is 7.8 with local attack vector, low complexity, low privileges required, no user interaction, unchanged scope, and high confidentiality, integrity, and availability impact. The supplied sources do not describe root cause details.
Likely exposure
Exposure is limited to affected Windows 10 builds listed in the source bundle: 1507, 1607, 1803, 1809, 1909, 2004, and 20H2. Risk is highest on unpatched endpoints, shared workstations, and VDI hosts where local compromise could become administrative compromise.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The CVSS temporal vector marks exploit code maturity as unproven. Treat this as a serious post-compromise privilege escalation risk, not confirmed internet-scale exploitation.
Researcher notes
Public details in the supplied bundle are sparse: Microsoft names WalletService EoP, affected Windows 10 versions, CVSS metrics, and vendor advisory links. No CWE, root-cause description, exploit narrative, or workaround is provided. Avoid assuming exploitability beyond the local, low-privilege CVSS conditions.
Mitigation direction
- Apply Microsoft’s security update or latest cumulative update for CVE-2021-1687.
- Prioritize affected Windows 10 endpoints with broad user access or elevated business sensitivity.
- Check MSRC guidance before applying compensating controls or exceptions.
- Remove or upgrade unsupported Windows 10 builds where normal patching is unavailable.
Validation and detection
- Inventory endpoints for the affected Windows 10 versions listed in the advisory.
- Verify security update compliance through endpoint management or vulnerability scanning.
- Confirm scanners no longer report CVE-2021-1687 on patched systems.
- Review exception lists for systems unable to receive Microsoft updates.
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-2021-1687 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
- Windows WalletService Elevation of Privilege VulnerabilityCVE reference · vendor-advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1687CVE 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.