CVE-2019-18978 The rack-cors rubygem may allow directory traveral

What is CVE-2019-18978?

CVE-2019-18978 is a medium-severity path traversal vulnerability in Canonical Ubuntu Linux, published on 14 Nov 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-22

Which versions are affected by CVE-2019-18978?

2 open source packages ship an affected version, including rack-cors. It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Rack-Cors Project Rack-Cors.

How do I fix CVE-2019-18978?

Upgrade rack-cors to 1.0.4 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2019-18978 being exploited?

There is no known exploitation of CVE-2019-18978 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2019-18978, DLA-2096-1, DLA-2389-1, DSA-4918-1, GHSA-pf8f-w267-mq2h, UBUNTU-CVE-2019-18978 and 1 more.