CVE-2018-12398 Security feature bypass in Firefox

What is CVE-2018-12398?

CVE-2018-12398 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 28 Feb 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

By using the reflected URL in some special resource URIs, such as chrome:, it is possible to inject stylesheets and bypass Content Security Policy (CSP). This vulnerability affects Firefox < 63.

Which versions are affected by CVE-2018-12398?

It affects 2 products.

Products include Canonical Ubuntu Linux, Mozilla Firefox.

How do I fix CVE-2018-12398?

Upgrade to a fixed version.

Is CVE-2018-12398 being exploited?

There is no known exploitation of CVE-2018-12398 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 GHSA-mmrj-hw4g-j8hv, UBUNTU-CVE-2018-12398.