CVE-2019-18978

Name: CVE-2019-18978
Creator: NVD / NIST
Published: 2019-11-14T21:15:12.17+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 2.46%

Last modified Jun 17, 2026

CVE-2019-18978 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for Ruby. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.. EPSS estimates a 2.46% chance of exploitation in the next 30 days.

Description

An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for Ruby. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

2.46%

82.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Rack-Cors Project	Rack-Cors	< 1.0.4
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Canonical	Ubuntu Linux	16.04

References

https://github.com/cyu/rack-cors/commit/e4d4fc362a4315808927011cbe5afcfe5486f17dPatch, Third Party Advisory
https://github.com/cyu/rack-cors/compare/v1.0.3...v1.0.4Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/02/msg00004.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00000.htmlMailing List, Third Party Advisory
https://usn.ubuntu.com/4571-1/Third Party Advisory
https://www.debian.org/security/2021/dsa-4918Third Party Advisory
https://github.com/cyu/rack-cors/commit/e4d4fc362a4315808927011cbe5afcfe5486f17dPatch, Third Party Advisory
https://github.com/cyu/rack-cors/compare/v1.0.3...v1.0.4Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/02/msg00004.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00000.htmlMailing List, Third Party Advisory
https://usn.ubuntu.com/4571-1/Third Party Advisory
https://www.debian.org/security/2021/dsa-4918Third Party Advisory

Timeline

Published: Nov 14, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-18978?

How severe is CVE-2019-18978?

CVE-2019-18978 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 2.46% probability of exploitation in the next 30 days.

How do I fix CVE-2019-18978?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-18978?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST