CVE-2009-0099
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 · uneditedThe Electronic Messaging System Microsoft Data Base (EMSMDB32) provider in Microsoft Exchange 2000 Server SP3 and Exchange Server 2003 SP2, as used in Exchange System Attendant, allows remote attackers to cause a denial of service (application outage) via a malformed MAPI command, aka "Literal Processing 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 · moderate confidenceA denial of service vulnerability in the EMSMDB32 (Electronic Messaging System Microsoft Data Base) provider affecting Microsoft Exchange 2000 Server SP3 and Exchange Server 2003 SP2. Remote attackers can trigger the vulnerability by sending malformed MAPI commands to the Exchange System Attendant service, causing the application to become unavailable.
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= 2000= 2003= 2007CVSS 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
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 checksWork through these to decide whether this CVE applies to you.
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Identify Exchange Server versionCheck the installed version by running 'reg query HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\Parameters /v 'Server Version'' or examining the Exchange System Manager. Alternatively, run 'Get-ExchangeServer' in Exchange Management Shell for Exchange 2007.Affected if The version matches Exchange 2000, Exchange 2003, or Exchange 2007.
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Verify System Attendant service statusCheck if the 'Microsoft Exchange System Attendant' service is running. In PowerShell, run 'Get-Service MSExchangeSA' on Exchange 2007, or check via Services console (services.msc) for Exchange 2000/2003.Affected if The service is running and started, making the vulnerability exploitable.
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Confirm MAPI over RPC exposureVerify that MAPI/RPC endpoints are enabled and accessible. Check registry key 'HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem\RPC\RPC Proxy Interface Identifier' or review the protocols enabled in Exchange System Manager for Exchange 2000/2003, or via 'Get-RpcClientAccess' in Exchange 2007.Affected if MAPI/RPC access is enabled, allowing remote attackers to send malformed MAPI commands.
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Assess network accessibility of RPC portsCheck if the Exchange server has TCP ports 135 (RPC Endpoint Mapper) and 1025-1026 (RPC dynamic ports) exposed to untrusted networks. Use 'netstat -an | findstr :135' or port scanning from an external host.Affected if RPC ports are reachable from untrusted networks, enabling remote exploitation.
You are affected if you run Exchange 2000, 2003, or 2007 with the System Attendant service running and MAPI/RPC ports exposed to network attackers.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataApply the relevant Microsoft security update for this vulnerability. Organizations running these legacy Exchange versions should consider upgrading to supported Exchange versions or migrating to modern platforms, as Exchange 2000 and 2003 are long past end-of-support.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-0099 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2009-0099 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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
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