#VU18031 Memory corruption in Mozilla Firefox - CVE-2019-9792

Vulnerability identifier: #VU18031

Vulnerability risk: High

CVSSv4.0: 7.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2019-9792

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: Yes

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

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error within the IonMonkey just-in-time (JIT) compiler that leaks an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. A remote attacker can trick the victim to visit a specially crafted web page, trigger memory corruption and execute arbitrary code on the system with privileges of the current user.

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

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 60.0 - 65.0.2

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2019-07/
https://bugzilla.mozilla.org/show_bug.cgi?id=1532599

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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.