CVE-2009-4419
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 · uneditedIntel Q35, GM45, PM45 Express, Q45, and Q43 Express chipsets in the SINIT Authenticated Code Module (ACM), which allows local users to bypass the Trusted Execution Technology protection mechanism and gain privileges by modifying the MCHBAR register to point to an attacker-controlled region, which prevents the SENTER instruction from properly applying VT-d protection while an MLE is being loaded.
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 confidenceThis vulnerability in Intel Q35, GM45, PM45, Q45, and Q43 Express chipsets allows local attackers to bypass Trusted Execution Technology (TXT) protection by modifying the MCHBAR register to point to an attacker-controlled memory region. This prevents the SENTER instruction from properly applying VT-d protection during MLE (Measured Launch Environment) loading, enabling privilege escalation.
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 dataall versionsall versionsall versionsall 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
- Local
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/AC:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify the Intel chipset model in the systemUse system information tools such as 'dmidecode -t baseboard', 'lspci', or check BIOS/UEFI information to identify the installed chipset model. Look for identifiers: Gm45, PM45, Q35, Q43, or Q45.Affected if The system uses an Intel Gm45, PM45 Express, Q35, Q43 Express, or Q45 chipset.
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Check if Trusted Execution Technology (TXT) is enabledOn Linux, use 'txt-stat' from the tboot package or check '/sys/kernel/security/txt0/ '是否存在. On Windows, check via 'msinfo32' or TPM/ms-tpm tools. TXT must be enabled in BIOS/UEFI and visible to the OS.Affected if TXT is currently enabled on the system, making the TXT boot path active and vulnerable to MCHBAR manipulation.
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Verify Intel VT-d is enabled in BIOS/UEFIEnter system BIOS/UEFI setup and navigate to Intel Virtualization Technology settings. VT-d (Virtualization Technology for Directed I/O) must be enabled for the attack to apply.Affected if VT-d is enabled in BIOS, which is required for the vulnerability to be exploitable.
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Check BIOS/firmware version against vendor patchesRetrieve the current BIOS version via 'dmidecode -s bios-version' on Linux or 'wmic bios get smbiosbiosversion' on Windows. Compare against Intel-provided BIOS updates for the specific chipset model.Affected if The BIOS version is older than Intel-released patches for CVE-2009-4419 and no vendor firmware update has been applied.
A system is affected if it contains an Intel Gm45, PM45, Q35, Q43, or Q45 chipset with TXT and VT-d enabled, and the BIOS firmware has not been updated from the original vulnerable version.
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 Intel-provided BIOS/firmware updates for affected chipsets and ensure TXT is properly configured; verify VT-d is enabled in BIOS and that SINIT ACM is updated to patched versions.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2009-4419 — 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-2009-4419 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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- Version or environment caveats, and links to real fixes
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