1) Type Confusion

EUVDB-ID: #VU18824

Risk: Critical

CVSSv3.1: 8.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2019-11707

CWE-ID: CWE-843 - Access of Resource Using Incompatible Type ('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 when manipulating JavaScript objects due to issues in Array.pop. A remote attacker can create a specially crafted web page, trick the victim into visiting it, trigger a type confusion error and execute arbitrary code on the target system.

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

Note: this vulnerability is being actively exploited in the wild along with SB2019062002 (CVE-2019-11708).

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Firefox ESR: 60.0 - 60.7.0

Mozilla Firefox: 61.0 - 67.0.2

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CPE2.3

• cpe:2.3:a:mozilla:firefox_esr:60.7.0:*:*:*:*:*:*:*
• Full software list in CPE2.3 format available after registration.

External links

http://www.mozilla.org/en-US/security/advisories/mfsa2019-18/
http://twitter.com/5aelo/status/1141273394723414016
http://twitter.com/SecurityGuyPhil/status/1141466335592869888

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?

Yes. This vulnerability is being exploited in the wild.