CVE-2018-3740 — A specially crafted HTML fragment can cause Sanitize gem for Ruby to allow non-w

A specially crafted HTML fragment can cause Sanitize gem for Ruby to allow non-whitelisted attributes to be used on a whitelisted HTML element.

01What is this vulnerability?

A specially crafted HTML fragment can cause Sanitize gem for Ruby to allow non-whitelisted attributes to be used on a whitelisted HTML element.

02Affected products

Vendor	Product	Versions
Ryan Grove	sanitize (ruby gem)	< 4.6.3

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2018-03-30T19:00:00.000Z
• Last modified: 2024-08-05T04:50:30.616Z

09References

• www.debian.org — https://www.debian.org/security/2018/dsa-4358
• github.com — https://github.com/rgrove/sanitize/issues/176
• about.gitlab.com — https://about.gitlab.com/2018/06/25/security-release-gitlab-11-dot-0-dot-1-relea…
• github.com — https://github.com/rgrove/sanitize/commit/01629a162e448a83d901456d0ba8b65f3b03d4…