Vulnerability in Mozilla Firefox

CVE-2020-6813

When protecting CSS blocks with the nonce feature of Content Security Policy, the @import statement in the CSS block could allow an attacker to inject arbitrary styles, bypassing the intent of the Content Security Policy. This vulnerability affects Firefox < 74.

EPSS: 0.012 (64.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-6813?
CVE-2020-6813 is a medium-severity vulnerability in Mozilla Firefox. CVSS score: 5.3/10. Published 2020-03-25.
How severe is CVE-2020-6813?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2020-6813 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.