Consul gem insufficient authentication check - Multiple powers in one controller are not always checked correctly

published 2019-09-23 7 y ago modified 2026-06-17 4 mo ago also GHSA-8jhx-9gf4-hhf5 , EUVD-2019-0660

cvss: 9.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.6%; EPSS 2.6% chance of exploitation in 30 days, percentile 85%
public exploits: 0; none known

The makandra consul gem through 1.0.2 for Ruby has Incorrect Access Control.

Patch / fix

fixed in 1

rubygems consul 1.0.3

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-2019-16377 updated 2025-11-21 cvss 3.7

consul: unauthenticated access to certain controller actions

Red Hat All currently supported Red Hat products
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

2.64% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/makandra/consul/issues/49 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
rubygems	consul	<1.0.3	1.0.3

Classification

Weakness

CWE-284 Improper Access Control

References

github.com /makandra/consul/issues/49
web, exploit, third-party-advisory
rubygems.org /gems/consul
web, product, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2019-16377
advisory
github.com /makandra/consul
package
github.com /rubysec/ruby-advisory-db/blob/c26fbc13435b8be448ad59131428538049d165e4/gems/consul/CVE-2019-16377.yml
web
github.com /rubysec/ruby-advisory-db/blob/master/gems/consul/CVE-2019-16377.yml
web

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.

Summary