SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-5116

Malicious extensions can inject frames from arbitrary origins into the loaded page and then interact with them, bypassing same-origin user expectations with this permission.

CRITICAL 9.8EPSS 1.17%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

WebExtensions with the "ActiveTab" permission are able to access frames hosted within the active tab even if the frames are cross-origin. Malicious extensions can inject frames from arbitrary origins into the loaded page and then interact with them, bypassing same-origin user expectations with this permission. This vulnerability affects Firefox < 58.

CVSS 3.0
9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
1.17% probability · 66th percentile
CISA KEV
Not listed
Weakness
CWE-346
Affected
mozilla/firefox · canonical/ubuntu linux
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.