UriApplication · Ruby Lang
CVE-2025-27221
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 · uneditedIn the URI gem before 1.0.3 for Ruby, the URI handling methods (URI.join, URI#merge, URI#+) have an inadvertent leakage of authentication credentials because userinfo is retained even after changing the host.
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 confidenceThe Ruby URI gem versions prior to 1.0.3 retain authentication credentials (userinfo) in URI handling methods (URI.join, URI#merge, URI#+) even after the host component changes. This causes inadvertent credential leakage when combining or manipulating URIs, potentially exposing credentials to unintended destinations.
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
UriApplication
< 0.11.3>= 0.12.0, < 0.12.4>= 0.13.0, < 0.13.2>= 1.0.0, < 1.0.3CVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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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Check installed URI gem versionRun `gem list uri` or inspect the Gemfile.lock for the uri gem version entryAffected if The version listed is less than 0.11.3, OR between 0.12.0 and 0.12.3, OR between 0.13.0 and 0.13.1, OR between 1.0.0 and 1.0.2
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Identify URI operations with authentication credentialsSearch codebase for uses of URI.join, URI#merge, or URI#+ (the + operator) where the URI contains userinfo in the format scheme://user:pass@host/pathAffected if Code uses these methods with URIs that include embedded credentials (userinfo)
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Verify if host component changes during URI manipulationReview the URI manipulation logic to determine if the host component differs between the base URI and the path/fragment being joined or mergedAffected if The host component changes during the URI operation (e.g., joining a path from a credentialized URI to a different host)
You are affected if the installed URI gem version falls within any of the affected ranges AND your code uses URI.join, URI#merge, or URI#+ with credential-containing URIs where the host may change.
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.
dbcve · scoped0.11.30.12.40.13.2
Upgrade the Ruby URI gem to version 1.0.3 or later. In Gemfile, specify gem 'uri', '>= 1.0.3' and run bundle update uri, then verify URI operations work correctly in affected code paths.
uri gem version 1.0.3 (or 0.13.2 / 0.12.4 / 0.11.3 for older release lines)
- Check the current version of the uri gem in your project with: gem list uri
- For Ruby projects using Bundler, update your Gemfile or Gemfile.lock: bundle update uri
- Alternatively, manually upgrade the gem: gem install uri -v 1.0.3
- After upgrading, verify the new version is installed: gem list uri
- Run your test suite to ensure the upgrade does not break existing functionality
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Uri
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 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 $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-27221 — 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-2025-27221 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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