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Fencer Vulns
medium 6.1

CVE-2018-11627 json

Sinatra Cross-site Scripting vulnerability

published 2018-05-31 8 y ago modified 2026-06-17 4 mo ago also GHSA-mq35-wqvf-r23c , EUVD-2018-0197

cvss
6.1
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

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

Patch / fix

  • rubygems sinatra 2.0.2
  • sinatrarb sinatra 2.0.2
  • ruby-sinatra Ubuntu 20.04 LTS 2.0.8.1-1
  • ruby-sinatra Ubuntu 22.04 LTS 2.0.8.1-2

ubuntu advisories UBUNTU-CVE-2018-11627

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • cfme cloudforms managementengine 5.9 5.9.8.1-1.el7cf
  • cfme-gemset cloudforms managementengine 5.9 5.9.8.1-1.el7cf
  • cfme-appliance cloudforms managementengine 5.9 5.9.8.1-1.el7cf
  • dbus-api-service cloudforms managementengine 5.9 1.0.1-3.2.el7cf
  • cfme-appliance-tools cloudforms managementengine 5.9 5.9.8.1-1.el7cf
  • cfme-appliance-common cloudforms managementengine 5.9 5.9.8.1-1.el7cf
  • cfme-amazon-smartstate cloudforms managementengine 5.9 5.9.8.1-1.el7cf
  • wmi cloudforms managementengine 5.10 1.3.14-7.el7cf

red hat advisories RHSA-2019:0315RHSA-2019:0212

  • rubygem-sinatra openSUSE Tumbleweed 2.2.0-1.1

opensuse advisories openSUSE-SU-2024:12033-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-11627 updated cvss 6.1

rubygem-sinatra: XSS in the 400 Bad Request page

  • Red Hat CloudForms Management Engine 5.9 cfme 5.9.8.1-1.el7cf, cfme-gemset 5.9.8.1-1.el7cf, cfme-appliance 5.9.8.1-1.el7cf, dbus-api-service 1.0.1-3.2.el7cf, cfme-appliance-tools 5.9.8.1-1.el7cf, cfme-appliance-common 5.9.8.1-1.el7cf, +1 more
    fixed: vendor fix RHSA-2019:0315
  • Red Hat CloudForms Management Engine 5.10 smem 1.4-1.el7cf, wmi 1.3.14-7.el7cf, ruby 2.4.5-90.el7cf, nginx 1.10.2-1.el7at, wxGTK3 3.0.3-5.el7at, prince 9.0r2-10.el7cf, +179 more
    fixed: vendor fix RHSA-2019:0212
  • Red Hat Ceph Storage 1.3 rubygem-sinatra Red Hat Enterprise Linux 6 pcs Red Hat Enterprise Linux 7 pcs, pcs-snmp, python-clufter Red Hat Enterprise Linux 8 pcs, pcs-snmp, rubygem-sinatra Red Hat Enterprise Linux OpenStack Platform 7 (Kilo) Operational Tools rubygem-sinatra Red Hat Enterprise MRG 2 rubygem-sinatra
    +8 more products
    Red Hat OpenStack Platform 8 (Liberty) Operational Tools rubygem-sinatra Red Hat OpenStack Platform 9 (Mitaka) Operational Tools rubygem-sinatra Red Hat OpenStack Platform 10 (Newton) Operational Tools rubygem-sinatra Red Hat OpenStack Platform 12 (Pike) Operational Tools rubygem-sinatra Red Hat Satellite 6 rubygem-sinatra Red Hat Software Collections rh-ror42-rubygem-sinatra, rh-ror50-rubygem-sinatra Red Hat Storage 3 pcs, rubygem-sinatra Red Hat Subscription Asset Manager rubygem-sinatra
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.16% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/sinatra/sinatra/issues/1428 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 6.1 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N
GitHub 3.0 6.1 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
rubygems sinatra
>=2.0.0, <2.0.2
2.0.2

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.