dbcve.org
SanitizeApplication · Sanitize Project

CVE-2023-23627

MEDIUM · 6.1 CVSS v3.1 Published 2023-01-28
Fix available
A fix is available. Upgrade to 6.0.1 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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
Sanitize is an allowlist-based HTML and CSS sanitizer. Versions 5.0.0 and later, prior to 6.0.1, are vulnerable to Cross-site Scripting. When Sanitize is configured with a custom allowlist that allows `noscript` elements, attackers are able to include arbitrary HTML, resulting in XSS (cross-site scripting) or other undesired behavior when that HTML is rendered in a browser. The default configurations do not allow `noscript` elements and are not vulnerable. This issue only affects users who are using a custom config that adds `noscript` to the element allowlist. This issue has been patched in version 6.0.1. Users who are unable to upgrade can prevent this issue by using one of Sanitize's default configs or by ensuring that their custom config does not include `noscript` in the element allowlist.

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

Sanitize versions 5.0.0 through 6.0.0 are vulnerable to XSS when configured with a custom allowlist that includes the `noscript` element. Attackers can inject arbitrary HTML through crafted input containing noscript tags, which browsers may render as HTML content (especially when JavaScript is disabled or in certain contexts), enabling XSS or other malicious behavior.

MitigationUpgrade to Sanitize version 6.0.1 or later, or remove `noscript` from any custom element allowlist configurations.

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
SanitizeApplication
Affected:>= 5.0.0, < 6.0.1

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 checks

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

  1. Determine the installed Sanitize gem version
    Run `gem list sanitize` or check your Gemfile.lock for the sanitize gem version entry
    Affected if The version listed is 5.0.0 through 6.0.0 (any version >= 5.0.0 and < 6.0.1)
  2. Locate Sanitize configuration files
    Search your codebase for instances of `Sanitize::Config` or calls to `Sanitize::HTML` that define custom allowlists, typically in config files, initializers, or directly in Ruby code
    Affected if A custom configuration is in use (rather than using only the built-in defaults like Sanitize::Config::RELAXED)
  3. Inspect the custom allowlist for the noscript element
    Examine the custom config for any :add_attributes, :allowed, or :elements section that explicitly includes 'noscript' as an allowed element
    Affected if The custom configuration explicitly allows the 'noscript' element in any element allowlist

You are affected if your Sanitize gem version is 5.0.0 through 6.0.0 AND you use a custom allowlist that includes the noscript element, as this enables XSS via injected noscript tags in user input.

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 6.0.1 or later
Fixed in 6.0.1
Interim mitigation

Upgrade to Sanitize version 6.0.1 or later, or remove `noscript` from any custom element allowlist configurations.

Recommended fix High confidence

6.0.1

  1. Update the Sanitize gem to version 6.0.1 or later by running `bundle update sanitize` or adding `gem 'sanitize', '~> 6.0'` to your Gemfile
  2. Run `bundle install` to install the updated gem
  3. Verify your application functions correctly with the new version, particularly any code that uses custom Sanitize configurations
  4. Test that the HTML sanitization still meets your security requirements with the updated library
Caveat As this is a major version bump from 5.x to 6.x, review the gem's changelog for any potential breaking changes in your specific use case

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

Fix this in Sanitize Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
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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-2023-23627 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data