NginxWeb server / proxy · F5
CVE-2013-4547
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 0.8.41 through 1.4.3 and 1.5.x before 1.5.7 allows remote attackers to bypass intended restrictions via an unescaped space character in a URI.
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 is a URI parsing vulnerability in nginx where an unescaped space character in a URI allows attackers to bypass intended security restrictions such as access control lists or location block matching rules. The vulnerability affects nginx versions 0.8.41 through 1.4.3 and 1.5.x before 1.5.7.
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
>= 0.8.41, < 1.4.4>= 1.5.0, <= 1.5.6= 1.3= 1.3= 1.3= 11.4= 12.2= 12.3= 13.1CVSS 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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Determine installed nginx versionRun 'nginx -v' or 'nginx -V' to see the exact version number. On some systems, check the package manager (dpkg -l nginx, rpm -qa nginx, or yum list nginx).Affected if The version is 0.8.41 through 1.4.3, or 1.5.0 through 1.5.6 (or specifically any version >= 0.8.41 and < 1.4.4, or >= 1.5.0 and <= 1.5.6).
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Identify location block configurationsReview all nginx configuration files (typically in /etc/nginx/, /etc/nginx/conf.d/, or /etc/nginx/sites-enabled/) for 'location' directives that define path-based access rules.Affected if Location blocks exist that enforce security restrictions based on URI paths - these are the rules that could be bypassed.
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Check for access control directivesSearch configuration files for 'allow' and 'deny' directives within location blocks or at server level, which define IP-based access control lists.Affected if allow/deny rules are defined, as these access controls could be bypassed by the URI parsing flaw.
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Verify vulnerability trigger conditionThe vulnerability exploits unescaped space characters in URIs (such as /location /admin). If your nginx handles URIs with spaces that are not properly normalized before access control checks, you may be affected.Affected if Your application or upstream systems send URIs containing spaces that reach nginx location matching or access control logic before proper normalization.
You are affected if your nginx version falls within 0.8.41-1.4.3 or 1.5.0-1.5.6 AND you have location-based access controls or path matching rules that could be bypassed via the space character URI parsing flaw.
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 data1.4.4
Upgrade nginx to version 1.4.4 or later (or 1.5.7+) to patch the URI parsing flaw, and verify that access controls and location matching rules function correctly after the update.
Fix this in Nginx
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 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 $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-4547 — 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-2013-4547 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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