#VU52342 Incorrect calculation in Mozilla Firefox and Firefox ESR

Published: 2021-04-19

Vulnerability identifier: #VU52342

Vulnerability risk: Low


CVE-ID: CVE-2021-29945


Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers

Vendor: Mozilla


The vulnerability allows a remote attacker to crash the application.

The vulnerability exists due to the WebAssembly JIT miscalculates the size of a return type, which leads to a null read. A remote attacker can create a specially crafted web page, trick the victim into visiting it and crash the browser.

Note, the vulnerability affects 32-bit platforms only.

Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 60.0 - 87.0

Firefox ESR: 78.0 - 78.9.0, 68.0 - 68.12.0, 60.0 - 60.9.0


External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

Latest bulletins with this vulnerability