CVE-2017-7820

Description

The "instanceof" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator, possibly tricking the browser or extension into mishandling the element. This vulnerability affects Firefox < 56.

Primary references

• security@mozilla.org — Third Party Advisory, VDB Entry
• security@mozilla.org — Third Party Advisory, VDB Entry
• security@mozilla.org — Exploit, Issue Tracking
• security@mozilla.org — Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory, VDB Entry
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory, VDB Entry
• af854a3a-2127-422b-91ae-364da2661108 — Exploit, Issue Tracking
• af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory