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Virtual PcApplication · Microsoft

CVE-2009-1542

HIGH · 9.0 CVSS v2.0 Published 2009-07-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
96/100
Remediation priority · Urgent
Remotely reachable 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 Virtual Machine Monitor (VMM) in Microsoft Virtual PC 2004 SP1, 2007, and 2007 SP1, and Microsoft Virtual Server 2005 R2 SP1, does not enforce CPU privilege-level requirements for all machine instructions, which allows guest OS users to execute arbitrary kernel-mode code and gain privileges within the guest OS via a crafted application, aka "Virtual PC and Virtual Server Privileged Instruction Decoding 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 Virtual Machine Monitor in Microsoft Virtual PC 2004 SP1, 2007, 2007 SP1, and Virtual Server 2005 R2 SP1 fails to enforce CPU privilege-level requirements for certain machine instructions. This allows an unprivileged guest OS user to execute privileged kernel-mode instructions by crafting specific applications, enabling arbitrary code execution with elevated privileges within the guest operating system.

MitigationApply Microsoft security updates for Virtual PC and Virtual Server, or migrate to newer virtualization platforms (Hyper-V, VMware, etc.) that have addressed this and subsequent vulnerabilities. Prioritize patching affected virtualization hosts and verify that guest VMs cannot bypass privilege boundaries.

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
Virtual PcApplication
Affected:= 2004= 2007
Virtual ServerApplication
Affected:= 2005

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
Authentication
Single
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:S/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 Virtual PC 2004 or 2007 is installed
    Open Control Panel > Programs and Features, or run 'wmic product get name,version' and look for 'Microsoft Virtual PC 2004' or 'Microsoft Virtual PC 2007' entries
    Affected if Version shown is 2004 (any SP) or 2007 (any SP)
  2. Check if Virtual Server 2005 is installed
    Open Control Panel > Programs and Features, or run 'wmic product get name,version' and look for 'Microsoft Virtual Server 2005' entries
    Affected if Version shown is 2005 R2 SP1 or earlier
  3. Verify Virtual PC service status
    Open Services (services.msc) and check for 'Virtual PC' service, or run 'sc query vpcsvc' to query service state
    Affected if Service exists and is running on a vulnerable version
  4. Verify Virtual Server service status
    Open Services (services.msc) and check for 'Virtual Server' service, or run 'sc query vssvr' to query service state
    Affected if Service exists and is running on a vulnerable version
  5. Identify running virtual machines on affected hosts
    Open Virtual PC or Virtual Server console and list active virtual machines, or check for associated processes like vpc.exe or vssvr.exe
    Affected if Any virtual machine is running on a host with vulnerable Virtual PC or Virtual Server installed

A system is affected if Microsoft Virtual PC 2004/2007 or Virtual Server 2005 R2 SP1 is installed and running, as these versions contain the privilege-level enforcement flaw in their virtual machine monitor.

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 updates for Virtual PC and Virtual Server, or migrate to newer virtualization platforms (Hyper-V, VMware, etc.) that have addressed this and subsequent vulnerabilities. Prioritize patching affected virtualization hosts and verify that guest VMs cannot bypass privilege boundaries.

Recommended fix Moderate confidence

This vulnerability was addressed via Microsoft Security Bulletin MS09-033 (KB969632). For customers still on older versions, consider upgrading to Hyper-V for modern virtualization needs.

  1. Check Microsoft Knowledge Base Article MS09-033 for the applicable security update for your version of Virtual PC or Virtual Server
  2. For Virtual PC 2004 SP1: Apply security update KB969632
  3. For Virtual PC 2007 and 2007 SP1: Apply security update KB969632
  4. For Virtual Server 2005 R2 SP1: Apply security update KB969632
  5. Restart the host system after applying the update
  6. Verify the update was installed successfully via Windows Update or Add/Remove Programs
Caveat The security update is a patch and should not introduce breaking changes; however, these older products (Virtual PC 2004/2007, Virtual Server 2005) are end-of-life and no longer supported.

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

Fix this in Virtual Pc Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2009-1542 in production — separate from our analysis above.

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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