CVE-2018-5168

Severity: medium (CVSS 5.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-06-11 · updated 2026-06-17

Description

Sites can bypass security checks on permissions to install lightweight themes by manipulating the "baseURI" property of the theme element. This could allow a malicious site to install a theme without user interaction which could contain offensive or embarrassing images. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

Affected products

Canonical Ubuntu Linux: 14.04, 16.04, 17.10, 18.04
Debian Linux: 7.0, 8.0, 9.0
Mozilla Firefox: before 52.8.0; before 60.0 — fixed in 52.8.0, 60.0
Mozilla Thunderbird: before 52.8.0 — fixed in 52.8.0
Mozilla Thunderbird ESR: before 52.8.0 — fixed in 52.8.0
RedHat Enterprise Linux Desktop: 6.0, 7.0
RedHat Enterprise Linux Server: 6.0, 7.0
RedHat Enterprise Linux Server Aus: 7.6
RedHat Enterprise Linux Server Eus: 7.5, 7.6
RedHat Enterprise Linux Server Tus: 7.6
RedHat Enterprise Linux Workstation: 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 52.8.0, 60.0; Mozilla Thunderbird 52.8.0; Mozilla Thunderbird ESR 52.8.0. Check the vendor advisory for mitigations.

References

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