CVE-2017-7820

MEDIUM

Firefox < 56 - Xray Wrapper Bypass via instanceof Operator

Title source: llm
STIX 2.1

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.

References (4)

Core 4
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1039465
Exploit, Issue Tracking x_refsource_confirm
https://bugzilla.mozilla.org/show_bug.cgi?id=1378207
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2017-21/
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/101057

Scores

CVSS v3 5.3
EPSS 0.0081
EPSS Percentile 74.4%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Details

Status published
Products (1)
mozilla/firefox < 55.0.3
Published Jun 11, 2018
Tracked Since Feb 18, 2026