SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-5143

URLs using "javascript:" have the protocol removed when pasted into the addressbar to protect users from cross-site scripting (XSS) attacks, but if a tab character is embedded in the "javascript:" URL the protocol is not removed and the script will…

MEDIUM 6.1EPSS 0.94%

Does this matter?

Lower severity and a low EPSS score (0.94%). Track it; it rarely justifies an emergency change on its own.

Description

URLs using "javascript:" have the protocol removed when pasted into the addressbar to protect users from cross-site scripting (XSS) attacks, but if a tab character is embedded in the "javascript:" URL the protocol is not removed and the script will execute. This could allow users to be socially engineered to run an XSS attack against themselves. This vulnerability affects Firefox < 59.

CVSS 3.0
6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
0.94% probability · 59th percentile
CISA KEV
Not listed
Weakness
CWE-79
Affected
mozilla/firefox · canonical/ubuntu linux
Source
security@mozilla.org

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