Security restrictions bypass in Mozilla Firefox - CVE-2018-12403

Vulnerability identifier: #VU15503

CSH Severity: Low

CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2018-12403

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to the mixed content warning is not displayed to users if a site is loaded over a HTTPS connection but loads a favicon resource over HTTP. A remote attacker can trick the victim into visiting a specially crafted website and bypass security restrictions.

Mozilla Firefox
Arch Linux
Ubuntu
firefox (Ubuntu package)

Update to version 63.0.

Mozilla Firefox - update to 63.0
firefox (Ubuntu package) - addressed in versions 63.0+build2-0ubuntu0.14.04.2, 63.0+build2-0ubuntu0.16.04.2, 63.0+build2-0ubuntu0.18.04.2, 63.0+build2-0ubuntu0.18.10.2

• https://www.mozilla.org/en-US/security/advisories/mfsa2018-26/

• Multiple vulnerabilities in Mozilla Firefox
• Arch Linux update for firefox
• Ubuntu update for firefox