CVE-2011-4973
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 · uneditedAuthentication bypass vulnerability in mod_nss 1.0.8 allows remote attackers to assume the identity of a valid user by using their certificate and entering 'password' as the password.
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 confidencemod_nss 1.0.8 contains an authentication bypass where remote attackers with a valid user certificate can authenticate by entering the literal string 'password' instead of the actual password. This allows attackers to assume the identity of legitimate certificate-holding users.
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= 1.0.8CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 mod_nss installationLocate the mod_nss module on the server (typically in the Apache modules directory or loaded via configuration) and determine its installed version using the server's module listing or package management systemAffected if The installed version is exactly 1.0.8
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Check if certificate-based authentication is enabledReview the mod_nss configuration files (usually in the Apache conf directory) for directives related to client certificate authentication such as NSSVerifyClient, NSSCertDatabase, or SSLVerifyClientAffected if Certificate-based authentication (client certificate verification) is configured and enabled on the server
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Confirm user certificates are acceptedExamine the NSS configuration for any NSSCertDB or certificate database settings that allow users to authenticate using client certificatesAffected if The server accepts client certificates for user authentication (not just server certificate validation)
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Test the authentication bypass conditionIf you have a valid client certificate installed, attempt to authenticate using the literal string 'password' as the password instead of the actual password associated with the certificateAffected if Authentication succeeds with 'password' when using a valid client certificate, confirming the bypass is present
You are affected if mod_nss version 1.0.8 is installed AND certificate-based client authentication is enabled, allowing the literal string 'password' to authenticate with a valid user certificate.
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 dataUpgrade mod_nss to a patched version if available, or disable certificate-based authentication until a fix can be applied. If upgrading is not possible, implement additional authentication controls such as IP-based restrictions or multi-factor authentication.
- Consultation4.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2011-4973 — 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-2011-4973 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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