Security readout for executives and security teams
Plain-English summary
CVE-2025-21363 is a high-severity Microsoft Word remote code execution issue. A successful attack could let code run on an affected Office installation after required user interaction. The provided sources identify Microsoft 365 Apps for Enterprise and Office LTSC editions, including Mac LTSC editions, as affected.
Executive priority
Treat this as a high-priority workstation patching issue, especially for teams handling outside documents. There is no supplied evidence of active exploitation, but the impact is high if exploited successfully.
Technical view
The CVSS 3.1 score is 7.8 with AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The listed weakness is CWE-822. The source bundle does not provide root-cause detail beyond Microsoft Word remote code execution and the affected Office product versions.
Likely exposure
Exposure is likely where affected Microsoft Word or Office builds are installed: Microsoft 365 Apps for Enterprise 16.0.1, Office LTSC 2024 16.0.0, Office LTSC for Mac 2021 16.0.1, or Office LTSC for Mac 2024 16.0.0.
Exploitation context
The provided data does not show active exploitation. KEV is false, and the CVSS exploit maturity value is E:U, meaning exploitation is unproven in the supplied source bundle. User interaction is required according to the CVSS vector.
Researcher notes
The bundle lacks detailed exploit mechanics, attack preconditions beyond CVSS, and fixed build identifiers. Validation should stay focused on product/version exposure, MSRC update status, and whether Word document handling creates meaningful business exposure.
Mitigation direction
- Apply Microsoft updates for CVE-2025-21363 from the MSRC advisory.
- Confirm affected Microsoft 365 Apps and Office LTSC installations are on fixed builds.
- Prioritize endpoints that open externally supplied Word documents.
- Follow Microsoft guidance if additional mitigations or servicing notes are published.
Validation and detection
- Inventory Office and Microsoft 365 Apps versions across Windows and Mac endpoints.
- Compare installed builds against the affected products and versions in the advisory.
- Verify endpoint patch status after Microsoft updates are deployed.
- Review mail, web, and endpoint controls for handling untrusted Word documents.
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.
CWE-822: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution 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-2025-21363 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:N/UI:R/S:U/C:H/I:H/A:H/E:U/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.
SSVC decision data
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:N/UI:R/S:U/C:H/I:H/A:H/E:U/RC:C1.85.9microsoftVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Microsoft Word Remote Code Execution VulnerabilityCVE reference, microsoft · vendor-advisory, patch
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.
Untrusted Pointer Dereference
Untrusted Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.