CVE-2009-3675
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 · uneditedLSASS.exe in the Local Security Authority Subsystem Service (LSASS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP2 allows remote authenticated users to cause a denial of service (CPU consumption) via a malformed ISAKMP request over IPsec, aka "Local Security Authority Subsystem Service Resource Exhaustion 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 confidenceA resource exhaustion vulnerability in LSASS.exe allows remote authenticated users to cause denial of service by sending malformed ISAKMP requests over IPsec. The malformed requests trigger excessive CPU consumption in the Local Security Authority Subsystem Service.
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= sp4all versionsall versionsCVSS 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
- None
- Integrity
- None
- Availability
- Complete
AV:N/AC:L/Au:S/C:N/I:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify the Windows versionRun 'winver' or check System Properties to determine if the OS is Windows 2000 SP4, Windows 2003 Server (any edition), or Windows XP (any edition). Alternatively, run 'systeminfo' from command line and look at the OS Name and OS Version fields.Affected if The installed OS is Windows 2000 Service Pack 4, Windows 2003 Server (any version), or Windows XP (any version).
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Verify IPsec service statusOpen Services (services.msc) and check if 'IKE and AuthIP IPsec Keying Modules' service is running, or run 'sc query IKEEXT' from an elevated command prompt.Affected if The IPsec keying module service is running, indicating IPsec functionality is enabled on the system.
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Check for ISAKMP listenerRun 'netstat -ano | findstr :500' to see if UDP port 500 (ISAKMP) is listening, or use 'netsh ipsec dynamic show all' to view active IPsec policies.Affected if The system is listening on UDP port 500 (ISAKMP) or has active IPsec policies configured, meaning it can receive the malformed requests.
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Confirm LSASS.exe is the targetOpen Task Manager or run 'tasklist | findstr lsass.exe' to verify the Local Security Authority Subsystem Service process is running.Affected if LSASS.exe is running (which is default on affected systems).
A system is affected if it is running Windows 2000 SP4, Windows 2003 Server, or Windows XP, has IPsec/IKE services enabled, and is exposed to network ISAKMP traffic on UDP port 500.
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 Microsoft security update MS09-055 or subsequent relevant patches. For legacy systems (Windows 2000/XP/Server 2003), consider IPsec filtering to block unauthorized ISAKMP traffic or upgrade to supported Windows versions.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-3675 — 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-2009-3675 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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- 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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