CVE-2021-23957 Security feature bypass in Firefox

High 7.4 Published Updated

Attackers can escape iframe sandbox restrictions on Firefox for Android by exploiting the intent URL scheme, bypassing security controls.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2021-23957?

CVE-2021-23957 is a high-severity vulnerability in Mozilla Firefox, published on 26 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Navigations through the Android-specific `intent` URL scheme could have been misused to escape iframe sandbox. Note: This issue only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 85.

Which versions are affected by CVE-2021-23957?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2021-23957?

Upgrade to a fixed version.

Is CVE-2021-23957 being exploited?

There is no known exploitation of CVE-2021-23957 in the wild and no public exploit code.

All Mozilla Firefox vulnerabilities

Sources

Also known as GHSA-r56v-99h2-76vh.

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