CVE-2017-7820 Security feature bypass in Firefox

What is CVE-2017-7820?

CVE-2017-7820 is a medium-severity vulnerability in Mozilla Firefox, published on 11 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Which versions are affected by CVE-2017-7820?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2017-7820?

Upgrade to a fixed version.

Is CVE-2017-7820 being exploited?

There is no known exploitation of CVE-2017-7820 in the wild and no public exploit code.

Other vulnerabilities in Mozilla Firefox

• CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Exploited Critical 10.0
• CVE-2010-3765 Mozilla Multiple Products Remote Code Execution Exploited Critical 9.8
• CVE-2022-26486 Mozilla Firefox Use-After-Free Exploited Critical 9.6
• CVE-2022-26485 Mozilla Firefox Use-After-Free Exploited High 8.8
• CVE-2019-11707 Mozilla Firefox and Thunderbird Type Confusion Exploited High 8.8

All Mozilla Firefox vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-hq9m-2fcc-v974, UBUNTU-CVE-2017-7820.