CVE-2018-11627 — Sinatra before 2

Sinatra before 2.0.2 has XSS via the 400 Bad Request page that occurs upon a params parser exception.

01What is this vulnerability?

Sinatra before 2.0.2 has XSS via the 400 Bad Request page that occurs upon a params parser exception.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

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: 2018-05-31T19:00:00.000Z
• Last modified: 2024-08-05T08:17:08.627Z

09References

• github.com — https://github.com/sinatra/sinatra/issues/1428
• access.redhat.com — https://access.redhat.com/errata/RHSA-2019:0315
• access.redhat.com — https://access.redhat.com/errata/RHSA-2019:0212
• github.com — https://github.com/sinatra/sinatra/commit/12786867d6faaceaec62c7c2cb5b0e2dc074d7…