Ubuntu LinuxOperating system · Canonical
CVE-2009-2474
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 · uneditedneon before 0.28.6, when OpenSSL or GnuTLS is used, 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.
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 confidenceThe neon library before 0.28.6 fails to properly validate X.509 certificates when OpenSSL or GnuTLS is used. The vulnerability stems from improper handling of null characters ('\0') in the Common Name (CN) field of the certificate subject. An attacker can craft a certificate with a domain like 'legitimate.com\0.malicious.com', causing SSL validation to be bypassed for the legitimate domain while presenting a certificate for the attacker's domain.
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
Ubuntu LinuxOperating system
= 6.06= 8.04= 8.10= 9.04
FedoraOperating system
= 10= 11< 0.28.6< 10.6.5CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- None
AV:N/AC:M/Au:N/C:P/I:P/A:N
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 neon library installationRun 'dpkg -l | grep neon' on Debian/Ubuntu, 'rpm -qa | grep neon' on Fedora/RHEL, or check for libneon.so in /usr/lib/Affected if neon library version is found to be below 0.28.6 or the package version matches affected Ubuntu (6.06, 8.04, 8.10, 9.04) or Fedora (10, 11) releases
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Determine exact neon versionIf neon is installed, run 'neon-config --version' or check the library file version with 'strings /usr/lib/libneon.so | grep -i version' or 'neon-config --version'Affected if Version returned is lower than 0.28.6
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Verify SSL/TLS certificate validation is in useInspect application logs or configuration for SSL/TLS usage with neon (look for HTTPS/WebDAV connections, 'SSL', 'TLS', or 'https' in URLs). Check if the application explicitly enables certificate validation (look for NE_SSL_NEVER_VERIFY vs NE_SSL_CTX_DEFAULT or similar options)Affected if Application uses neon for HTTPS/WebDAV connections with certificate validation enabled (the vulnerable code path)
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Check OpenSSL or GnuTLS library versionRun 'openssl version' and/or 'gnutls-cli --version' to identify which TLS backend is used with neonAffected if OpenSSL or GnuTLS is installed and being used by neon for SSL/TLS (required condition for this vulnerability)
You are affected if neon library version is below 0.28.6 AND your application uses neon for SSL/TLS connections with certificate validation against OpenSSL or GnuTLS.
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 data0.28.610.6.5
Upgrade neon library to version 0.28.6 or later which properly validates and rejects certificates containing null characters in the CN field.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-2474 — 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-2009-2474 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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