dbcve.org
Windows 2003 ServerOperating system · Microsoft

CVE-2010-2566

HIGH · 9.3 CVSS v2.0 Published 2010-08-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
The Secure Channel (aka SChannel) security package in Microsoft Windows XP SP2 and SP3, and Windows Server 2003 SP2, does not properly validate certificate request messages from TLS and SSL servers, which allows remote servers to execute arbitrary code via a crafted SSL response, aka "SChannel Malformed Certificate Request Remote Code Execution Vulnerability."

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 · high confidence

The Secure Channel (SChannel) security package in Windows XP SP2/SP3 and Windows Server 2003 SP2 fails to properly validate certificate request messages from TLS/SSL servers during the handshake process, allowing a remote malicious server to send a crafted SSL response that can trigger a buffer overflow and achieve remote code execution on the client.

MitigationApply Microsoft security update MS10-049 which addresses this SChannel vulnerability, or migrate from these end-of-life operating systems to supported Windows versions.

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 2003 ServerOperating system
Affected:all versions
Windows Server 2003Operating system
Affected:all versions
Windows XpOperating system
Affected:all versions

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
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:M/Au:N/C:C/I:C/A:C

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. Identify the Windows version
    Run 'winver' or check System Properties to confirm the exact Windows version and service pack level
    Affected if The system is running Windows XP (any SP) or Windows Server 2003 (any SP)
  2. Verify SChannel is in use
    SChannel is the default TLS/SSL security provider on affected systems. Check via registry at HKLM\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL, or simply note that any SSL/TLS application using Windows APIs will invoke SChannel
    Affected if SChannel is enabled (default state on affected OS versions)
  3. Check for MS10-049 security update
    Open Control Panel > Programs and Features > View installed updates, or run 'wmic qfe list' and search for KB980088 (the update that addresses CVE-2010-2566)
    Affected if The MS10-049 update (KB980088) is NOT installed
  4. Assess network exposure
    Determine if the system connects to untrusted networks or external SSL/TLS servers that could impersonate a legitimate server during TLS handshake
    Affected if The system can receive SSL/TLS connections from or initiate them to untrusted remote servers

A system is affected if it runs Windows XP or Windows Server 2003, uses SChannel for TLS/SSL (default), lacks the MS10-049 (KB980088) update, and is exposed to potentially malicious TLS/SSL servers.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Microsoft security update MS10-049 which addresses this SChannel vulnerability, or migrate from these end-of-life operating systems to supported Windows versions.

Recommended fix High confidence

Migrate to a supported Windows version (Windows 10/11 for workstations, Windows Server 2016 or later for servers)

  1. Note: Windows XP and Windows Server 2003 reached end of life in 2014 and 2015 respectively and no longer receive security updates from Microsoft.
  2. This vulnerability was addressed by Microsoft Security Bulletin MS10-049, an out-of-band patch released August 10, 2010.
  3. The recommended remediation is to migrate from unsupported Windows XP and Windows Server 2003 systems to a supported operating system version.
  4. If migration is not immediately possible, verify whether MS10-049 can still be applied from Microsoft Update Catalog or your internal patch repository.
  5. Ensure network segmentation isolates legacy systems and restrict their ability to initiate TLS/SSL connections to untrusted servers.
Caveat Migration from Windows XP/2003 may require application compatibility testing and legacy software replacement; these OS versions are no longer supported and receive no security patches

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

Fix this in Windows 2003 Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,690
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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-2010-2566 in production — separate from our analysis above.

No notes yet

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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