XSS in Mozilla Firefox

CVE-2017-7823

The content security policy (CSP) "sandbox" directive did not create a unique origin for the document, causing it to behave as if the "allow-same-origin" keyword were always specified. This could allow a Cross-Site Scripting (XSS) attack to be launched from unsafe content. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.015 (71.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2017-7823?
CVE-2017-7823 is a medium-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2018-06-11.
How severe is CVE-2017-7823?
Medium severity. CVSS v3 base score is 5.4 out of 10.