Vulnerability identifier: #VU63501

Vulnerability risk: High

CVSSv3.1: 7.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2022-1802

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers
Firefox for Android
Mobile applications / Apps for mobile phones

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to prototype pollution in Top-Level Await implementation. A remote attacker can trick the victim to visit a specially crafted website, corrupt the methods of an Array object in JavaScript via prototype pollution and execute arbitrary JavaScript code in a privileged context.

Successful exploitation of the vulnerability may allow an attacker to compromise the affected system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 90.0 - 100.0.1

Firefox ESR: 91.0 - 91.9.0

Firefox for Android: 90.1.0 - 100.2.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2022-19/
http://www.zerodayinitiative.com/advisories/ZDI-22-799/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.