dbcve.org
Windows 2000Operating system · Microsoft

CVE-2009-0090

HIGH · 9.3 CVSS v2.0 Published 2009-10-14
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
Microsoft .NET Framework 1.0 SP3, 1.1 SP1, and 2.0 SP1 does not properly validate .NET verifiable code, which allows remote attackers to obtain unintended access to stack memory, and execute arbitrary code, via (1) a crafted XAML browser application (XBAP), (2) a crafted ASP.NET application, or (3) a crafted .NET Framework application, aka "Microsoft .NET Framework Pointer Verification 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

This vulnerability in Microsoft .NET Framework 1.0 SP3, 1.1 SP1, and 2.0 SP1 allows attackers to bypass pointer verification in .NET verifiable code, enabling unintended stack memory access and arbitrary code execution through malicious XBAP, ASP.NET, or standalone .NET applications.

MitigationApply the Microsoft security update for this vulnerability or migrate affected systems to supported .NET Framework versions (3.5 SP1 or higher) that are not affected by this flaw.

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 2000Operating system
Affected:all versions
.net FrameworkApplication
Affected:= 1.1= 2.0= 3.5= 1.0
Windows Server 2003Operating system
Affected:all versions
Windows Server 2008Operating system
Affected:all versions
Windows VistaOperating system
Affected:all versions
Windows 7Operating 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. Check if .NET Framework is installed
    Open Registry Editor and navigate to HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP. Look for subkeys starting with 'v' (e.g., v1.0, v1.1, v2.0.50727, v3.0, v3.5). If no such keys exist, .NET Framework is not installed.
    Affected if Any .NET Framework subkey exists under the NDP path
  2. Identify installed .NET Framework version
    For each .NET version subkey found, query the 'Version' value in the registry: reg query 'HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\[VersionKey]' /v Version. Record the exact version number.
    Affected if Version shows 1.0.x, 1.1.x, 2.0.x, or 3.5.x (any release within those major version families)
  3. Check Service Pack level for .NET 1.0 or 1.1
    Query the SP value: reg query 'HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.0.3705' /v SP (for 1.0) or reg query 'HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322' /v SP (for 1.1). The SP value indicates the service pack number.
    Affected if For .NET 1.0: SP is less than 3. For .NET 1.1: SP is less than 1.
  4. Check Service Pack level for .NET 2.0
    Query: reg query 'HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727' /v SP. The SP value indicates the service pack number installed.
    Affected if SP value is less than 1 (meaning no SP1 or higher is installed)
  5. Confirm the Install state
    Verify the Install value is set to 1: reg query 'HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\[VersionKey]' /v Install. This confirms the version is fully installed and not just a partial installation.
    Affected if Install value equals 1

A system is affected if .NET Framework 1.0 SP3 or lower, 1.1 SP1 or lower, 2.0 SP1 or lower, or any 3.5 version is installed with Install=1 and the system runs verifiable .NET code (which is enabled by default).

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 the Microsoft security update for this vulnerability or migrate affected systems to supported .NET Framework versions (3.5 SP1 or higher) that are not affected by this flaw.

Recommended fix High confidence

Microsoft .NET Framework 3.5 SP1 or later (or migrate to .NET Framework 4.x if application compatibility permits)

  1. Install the appropriate Microsoft security update for your .NET Framework version: KB958481 for .NET Framework 1.0 SP3, KB958483 for .NET Framework 1.1 SP1, and KB958484 for .NET Framework 2.0 SP1
  2. Alternatively, upgrade to a newer .NET Framework version (3.5 SP1 or later) which includes the security fix
  3. After applying the patch or upgrade, restart affected services and servers
  4. Verify the update was applied successfully via Windows Update or by checking installed updates
Caveat Applications targeting .NET Framework 1.0/1.1/2.0 may require compatibility testing when migrating to newer versions; some APIs may behave differently

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

Fix this in Windows 2000 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2009-0090 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