Security readout for executives and security teams
Plain-English summary
CVE-2021-42275 is a high-severity Microsoft COM for Windows remote code execution flaw. A successful attacker with low privileges could potentially run code on affected Windows systems without user interaction, creating risk to confidentiality, integrity, and availability. The sources show broad Windows client and server impact and point to Microsoft guidance for official updates.
Executive priority
Prioritize remediation in the normal high-severity Windows patch cycle, accelerating for exposed servers, privileged-user workstations, and legacy systems. No source confirms active exploitation, but the impact profile supports prompt patch validation.
Technical view
The CVSS 3.1 vector is AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, score 8.8. It affects multiple Windows versions, including Windows 7, 8.1, 10, and Windows Server 2008 through 2022 variants. The bundle does not provide CWE, vulnerable component internals, or exploit mechanics beyond Microsoft COM RCE classification.
Likely exposure
Organizations running affected Windows desktop or server versions listed by Microsoft are potentially exposed, especially if systems are unpatched or legacy. Exposure should be assessed by exact OS version, architecture, and patch level against the MSRC advisory.
Exploitation context
The provided bundle does not establish active exploitation. KEV is false, and the CVSS temporal metric marks exploit code maturity as unproven. Treat as serious because exploitation requires only low privileges, low complexity, network access, and no user interaction.
Researcher notes
Available public data is thin: the bundle provides Microsoft’s RCE classification, affected platforms, CVSS vector, and advisory reference, but not root cause, CWE, proof-of-concept status, or detailed attack path. Avoid assuming exploitability beyond the documented CVSS conditions.
Mitigation direction
- Apply Microsoft security updates referenced by the MSRC advisory.
- Prioritize internet-facing, shared, and high-value Windows servers.
- Patch unsupported or legacy Windows systems through available extended support channels.
- Reduce unnecessary network exposure to affected Windows hosts.
- Check Microsoft guidance for any supersedence or platform-specific update notes.
Validation and detection
- Inventory Windows versions against the affected product list.
- Confirm installation of the relevant Microsoft security update for each platform.
- Review vulnerability scanner results for CVE-2021-42275 coverage.
- Check Microsoft update history or endpoint management compliance reports.
- Validate legacy systems are patched, isolated, or formally risk accepted.
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.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-42275 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
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/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-2021-42275CVE 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.