Security readout for executives and security teams
Plain-English summary
CVE-2025-21374 is a Windows CSC Service information disclosure issue. A low-privileged local attacker could potentially read sensitive information. It does not indicate code execution, system takeover, or service disruption in the provided sources.
Executive priority
Handle as a normal-to-elevated monthly patch priority. The main risk is sensitive data exposure from systems where an attacker already has local low-privileged access. Accelerate remediation for shared workstations, terminal servers, and sensitive Windows servers.
Technical view
Microsoft rates this as CVSS 5.5, medium. The vector is local, low complexity, low privileges required, no user interaction, unchanged scope, high confidentiality impact, and no integrity or availability impact. CWE-125 indicates an out-of-bounds read class issue.
Likely exposure
Exposure is likely on Windows clients and servers listed by Microsoft, including multiple Windows 10, Windows 11, and Windows Server versions through Server 2025. Systems with untrusted or broadly available local user access have higher practical concern.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Exploit maturity is listed as unproven. Treat this as patchable exposure, not a confirmed active campaign based on the provided evidence.
Researcher notes
Key constraints are local attack vector, low privileges, no user interaction, and confidentiality-only impact. The provided data names the vulnerable component and CWE class but does not include root-cause detail, proof of exploitation, or compensating mitigations beyond vendor patching.
Mitigation direction
- Apply Microsoft security updates referenced by the MSRC advisory.
- Prioritize affected Windows endpoints and servers with shared local user access.
- Check Microsoft guidance for systems that cannot be patched promptly.
- Track remediation through endpoint management and server patch reporting.
Validation and detection
- Inventory Windows versions against Microsoft’s affected product list.
- Confirm the relevant MSRC security update is installed.
- Verify scanner findings map to CVE-2025-21374 and affected builds.
- Review patch exceptions for business justification and expiry dates.
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-125: 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 lookupCVE-2025-21374 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:H/I:N/A:N/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.
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:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C1.83.6microsoftVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/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
- Windows CSC Service Information Disclosure 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.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.