NarouApplication · Narou Project

CVE-2021-35514

CRITICAL · 9.8 CVSS v3.1 Published 2021-06-28
Fix available
A fix is available. Upgrade to 3.8.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
Narou (aka Narou.rb) before 3.8.0 allows Ruby Code Injection via the title name or author name of a novel.

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 confidence

Narou.rb versions before 3.8.0 contain a Ruby code injection vulnerability. Attackers can inject arbitrary Ruby code through the title name or author name fields of a novel, potentially achieving remote code execution on the affected system.

MitigationUpgrade Narou.rb to version 3.8.0 or later to remediate the code injection vulnerability. If direct upgrade is not possible, implement input validation and sanitization on all novel title and author name inputs.

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
NarouApplication
Affected:< 3.8.0

CVSS 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:3.1/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 checks

Work through these to decide whether this CVE applies to you.

  1. Locate Narou.rb installation
    Run 'which narou' on Linux/macOS or check common install paths like 'C:\Ruby\bin\narou.bat' on Windows. If installed via gem, run 'gem list narou'.
    Affected if Narou.rb is not found on the system, then the user is not affected.
  2. Determine installed version
    Run 'narou --version' or 'narou -v' from the command line. The output will display the version number in format like '3.7.x'.
    Affected if The displayed version number is less than 3.8.0 (for example 3.7.5, 3.6.0, etc.).
  3. Verify novel library is in use
    Check if the user has imported or manages any novel files. Run 'narou list' to see if any novels are stored in the library. Look for a '~/narou' or '~/.narou' directory containing novel data.
    Affected if Novels exist in the library and the title/author metadata fields are populated, making the injection points accessible.
  4. Inspect novel data storage
    Examine the novel storage location (typically '~/narou/*.yaml' or database file). Open any YAML file in the data directory to view stored title and author name fields.
    Affected if Title or author name fields contain unsanitized or potentially malicious content from external sources.

The user is affected if Narou.rb version is below 3.8.0 and the novel library feature with title/author fields is actively used or contains imported novel data.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

dbcve · scoped
Upgrade available Upgrade to 3.8.0 or later
Fixed in 3.8.0
Interim mitigation

Upgrade Narou.rb to version 3.8.0 or later to remediate the code injection vulnerability. If direct upgrade is not possible, implement input validation and sanitization on all novel title and author name inputs.

Recommended fix Moderate confidence

Narou 3.8.0

  1. Check current Narou version using `narou version` or equivalent command
  2. Update Narou to version 3.8.0 or later using the package manager or gem update command (e.g., `gem install narou` or `narou update`)
  3. Verify the installation was successful by checking the version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Narou Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-35514 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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