RailsApplication · Rubyonrails
CVE-2013-0333
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 · uneditedlib/active_support/json/backends/yaml.rb in Ruby on Rails 2.3.x before 2.3.16 and 3.0.x before 3.0.20 does not properly convert JSON data to YAML data for processing by a YAML parser, which allows remote attackers to execute arbitrary code, conduct SQL injection attacks, or bypass authentication via crafted data that triggers unsafe decoding, a different vulnerability than CVE-2013-0156.
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 vulnerability exists in Rails' JSON parsing backend that converts JSON to YAML before parsing. The lib/active_support/json/backends/yaml.rb file fails to properly sanitize input during JSON-to-YAML conversion, allowing attackers to inject malicious YAML payloads that trigger unsafe YAML deserialization, leading to remote code execution, SQL injection, or authentication bypass.
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
RailsApplication
= 2.3.0= 2.3.1= 2.3.2= 2.3.3= 2.3.4= 2.3.9= 2.3.10= 2.3.11= 2.3.12= 2.3.13= 2.3.14= 2.3.15
Ruby On RailsApplication
= 3.0.4CVSS 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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Identify Rails versionRun 'rails -v' in the application directory, or check the Gemfile.lock for the 'rails' gem version, or check config/environment.rb for Rails::VERSION::STRINGAffected if The installed Rails version is 2.3.0-2.3.15 or exactly 3.0.4
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Check JSON backend configurationInspect the application configuration for ActiveSupport::JSON.backend setting. Look in config/initializers/, config/application.rb, or environment-specific config files for a line like 'ActiveSupport::JSON.backend = "YAML"'Affected if The JSON backend is explicitly set to YAML or uses the default YAML backend in affected Rails versions
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Verify JSON input processingSearch the codebase for JSON parsing calls such as 'JSON.parse', 'ActiveSupport::JSON.decode', or controller actions accepting JSON ( Content-Type: application/json)Affected if The application processes user-supplied JSON input without additional sanitization layers
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Check for YAML unsafe deserialization usageSearch for direct YAML.load, YAML.safe_load, or Psych.safe_load calls in the application code that handle external inputAffected if The application uses unsafe YAML loading on data that could originate from user JSON input
You are affected if you run Rails 2.3.0-2.3.15 or Rails 3.0.4, process JSON input, and use or default to the YAML-based JSON backend for parsing.
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 Ruby on Rails to version 2.3.16+, 3.0.20+, or migrate to a patched version. Alternatively, disable the YAML-based JSON backend and use a safer JSON parser implementation.
Fix this in Rails
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-0333 — 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-2013-0333 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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