Multiple vulnerabilities in Mozilla Firefox and Firefox ESR

Published: 2018-10-03

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2018-12386 CVE-2018-12387
CWE-ID	CWE-843 CWE-193
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	Firefox ESR Client/Desktop applications / Web browsers Mozilla Firefox Client/Desktop applications / Web browsers
Vendor	Mozilla

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Type Confusion

EUVDB-ID: #VU15149

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-2018-12386

CWE-ID: CWE-843 - Type confusion

Exploit availability: Yes

Description

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

The vulnerability exists due to a type confusion error in register allocation within the JavaScript engine. A remote attacker can create a specially crafted web page, trick the victim into visiting it, trigger a type confusion error that will allow arbitrary read and write operations within the sandboxed content process.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Firefox ESR: 60.0 - 60.2.1

Mozilla Firefox: 60.0 - 62.0.2

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2018-24/

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website.

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.

2) Off-by-one

EUVDB-ID: #VU15150