ChromeWeb browser · Google
CVE-2009-3456
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 · uneditedGoogle Chrome, possibly 3.0.195.21 and earlier, does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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 confidenceGoogle Chrome 3.0.195.21 and earlier fails to properly handle null bytes ('\0') embedded in the Common Name (CN) field of X.509 certificates. Attackers can obtain a legitimately signed certificate from a CA that appears valid for a trusted domain but actually contains a null byte followed by an attacker-controlled domain, causing Chrome to trust the certificate for the wrong domain and enabling man-in-the-middle attacks.
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
ChromeWeb browser
<= 3.0.195.21= 0.2.149.27= 0.2.149.29= 0.2.149.30= 0.2.152.1= 0.2.153.1= 0.3.154.0= 0.3.154.3= 0.4.154.18= 0.4.154.22= 0.4.154.31= 0.4.154.33CVSS 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
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:P/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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Find installed Google Chrome versionOpen Chrome, click the menu icon (three dots), select 'Help', then 'About Google Chrome' to display the current version numberAffected if The displayed version is 3.0.195.21 or earlier, or exactly matches one of these versions: 0.2.149.27, 0.2.149.29, 0.2.149.30, 0.2.152.1, 0.2.153.1, 0.3.154.0, 0.3.154.3, 0.4.154.18, 0.4.154.22, 0.4.154.31, or 0.4.154.33
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Verify SSL/TLS usageConfirm that the Chrome browser is being used to browse HTTPS sites; the vulnerability only applies when Chrome validates SSL certificatesAffected if Chrome is used for browsing HTTPS websites with certificate validation enabled
A user is affected if their installed Chrome version is 3.0.195.21 or earlier, or exactly matches any of the specific versions listed (0.2.x through 0.4.x series), and they browse HTTPS websites where Chrome performs certificate CN validation.
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 dataUpdate Google Chrome to a version that properly rejects null bytes in certificate CN fields, or ensure browsers are updated through automatic update mechanisms. For legacy systems that cannot be updated, consider using alternative browsers or implementing additional certificate validation at the network perimeter.
Fix this in Chrome
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-3456 — 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-2009-3456 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
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