NginxWeb server / proxy · F5
CVE-2011-4963
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 · uneditednginx/Windows 1.3.x before 1.3.1 and 1.2.x before 1.2.1 allows remote attackers to bypass intended access restrictions and access restricted files via (1) a trailing . (dot) or (2) certain "$index_allocation" sequences in a request.
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 confidencePath traversal vulnerability in nginx on Windows allows attackers to bypass access restrictions using trailing dots or $index_allocation sequences in URLs, potentially exposing restricted files through the web server.
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
NginxWeb server / proxy
>= 0.7.52, < 1.2.1= 1.3.0CVSS 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
- None
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:N/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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Confirm nginx is running on WindowsCheck the operating system (uname -a on Linux, systeminfo on Windows, or check if nginx.conf contains Windows-style paths). The vulnerability only affects nginx on Windows.Affected if The server is not running Windows - the vulnerability does not apply to Linux/Unix deployments.
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Identify installed nginx versionRun 'nginx -v' or 'nginx -V' to display the version. Alternatively, check the F5 nginx package version if installed via a package manager.Affected if The version is >= 0.7.52 AND < 1.2.1, OR the version is exactly 1.3.0.
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Locate the nginx configuration fileFind nginx.conf using 'nginx -t' to display the configuration path, or check default locations like /etc/nginx/nginx.conf or C:\nginx\conf\nginx.conf on Windows.Affected if No nginx.conf found - the server may not be running nginx.
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Check for access restriction directivesSearch the nginx.conf and included files for 'allow' or 'deny' directives within location blocks. These define IP-based access controls that the path traversal could bypass.Affected if No allow/deny directives are configured - the path traversal bypass would have no restrictions to circumvent.
The environment is affected if nginx is running on Windows with a version in the range 0.7.52 to 1.2.0 or exactly 1.3.0, AND the configuration contains access restrictions (allow/deny directives) that could be bypassed via trailing dots or $index_allocation sequences in URLs.
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 data1.2.1
Upgrade nginx to version 1.3.1+/1.2.1+ or later on Windows deployments to patch the path handling bypass.
Fix this in Nginx
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 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 $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-4963 — 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-2011-4963 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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