dbcve.org
Windows 10 1507Operating system · Microsoft

CVE-2025-21222

HIGH · 8.8 CVSS v3.1 Published 2025-04-08
Fix available
A fix is available. Upgrade to 10.0.10240.20978 / 10.0.14393.7969 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to execute code over a network.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Heap-based buffer overflow vulnerability in Windows Telephony Service permits remote code execution by an unauthorized attacker over the network. The vulnerability stems from improper bounds checking in memory allocation within the telephony service component.

MitigationApply Microsoft security updates for CVE-2025-21222 through Windows Update or enterprise patch management systems; verify telephony functionality post-patch in a staging environment before production deployment.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Windows 10 1507Operating system
Affected:< 10.0.10240.20978
Windows 10 1607Operating system
Affected:< 10.0.14393.7969
Windows 10 1809Operating system
Affected:< 10.0.17763.7136
Windows 10 21h2Operating system
Affected:< 10.0.19044.5737
Windows 10 22h2Operating system
Affected:< 10.0.19045.5737
Windows 11 22h2Operating system
Affected:< 10.0.22621.5189
Windows 11 23h2Operating system
Affected:< 10.0.22631.5189
Windows 11 24h2Operating system
Affected:< 10.0.26100.3775

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Windows version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' from command prompt
    Affected if The reported version falls within any of the affected ranges: Windows 10 1507 < 10.0.10240.20978, Windows 10 1607 < 10.0.14393.7969, Windows 10 1809 < 10.0.17763.7136, Windows 10 21h2 < 10.0.19044.5737, Windows 10 22h2 < 10.0.19045.5737, Windows 11 22h2 < 10.0.22621.5189, Windows 11 23h2 < 10.0.2263
  2. Identify telephony service status
    Run 'sc query TsvcService' or 'Get-Service -Name TsvcService' from an elevated command prompt
    Affected if The telephony service (TsvcService) is running on an affected Windows version
  3. Check if telephony service is network-exposed
    Review firewall rules for inbound access to telephony service ports using 'netsh advfirewall firewall show rule name=all' or check for open ports associated with the telephony service
    Affected if The telephony service is running AND network-accessible (listening on accessible ports) on an affected Windows version

You are affected if your Windows version is below any of the specified build numbers AND the Windows Telephony Service is running and network-accessible in your environment.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.10240.20978 / 10.0.14393.7969 / 10.0.17763.7136 or later
Fixed in 10.0.10240.2097810.0.14393.796910.0.17763.7136
Interim mitigation

Apply Microsoft security updates for CVE-2025-21222 through Windows Update or enterprise patch management systems; verify telephony functionality post-patch in a staging environment before production deployment.

Recommended fix High confidence

Windows 10 1507: 10.0.10240.20978+ | Windows 10 1607: 10.0.14393.7969+ | Windows 10 1809: 10.0.17763.7136+ | Windows 10 21h2: 10.0.19044.5737+ | Windows 10 22h2: 10.0.19045.5737+ | Windows 11 22h2: 10.0.22621.5189+ | Windows 11 23h2: 10.0.22631.5189+ | Windows 11 24h2: 10.0.26100.3775+

  1. 1. Identify the current Windows version by running 'winver' or checking System Properties
  2. 2. Determine which Windows 10 or 11 version is installed from the list of affected versions
  3. 3. Apply the appropriate Windows security update for CVE-2025-21222 from Microsoft Update Catalog or Windows Update
  4. 4. Alternatively, enable automatic Windows Updates to receive the security patch automatically
  5. 5. After installation, verify the Windows build number matches or exceeds the fixed version for your release
  6. 6. Restart the system if prompted to complete the update installation
Caveat Standard Windows update risks apply (interruption during install, potential driver compatibility issues); backup data before applying updates

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1507 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-21222 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data