What’s Vulnerable › Vulnerabilities

CVE-2018-5133

• Severity: medium (CVSS 6.5 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-200

Description

If the "app.support.baseURL" preference is changed by a malicious local program to contain HTML and script content, this content is not sanitized. It will be executed if a user loads "chrome://browser/content/preferences/in-content/preferences.xul" directly in a tab and executes a search. This stored preference is also executed whenever an EME video player plugin displays a CDM-disabled message as a notification message. This vulnerability affects Firefox < 59.

Affected products

• Canonical Ubuntu Linux: 14.04, 16.04, 17.10
• Mozilla Firefox: before 59.0 — fixed in 59.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 59.0. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/103386
• http://www.securitytracker.com/id/1040514
• https://bugzilla.mozilla.org/show_bug.cgi?id=1430511
• https://bugzilla.mozilla.org/show_bug.cgi?id=1430974
• https://usn.ubuntu.com/3596-1/
• https://www.mozilla.org/security/advisories/mfsa2018-06/
• http://www.securityfocus.com/bid/103386
• http://www.securitytracker.com/id/1040514
• https://bugzilla.mozilla.org/show_bug.cgi?id=1430511
• https://bugzilla.mozilla.org/show_bug.cgi?id=1430974
• https://usn.ubuntu.com/3596-1/
• https://www.mozilla.org/security/advisories/mfsa2018-06/

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