Zero-day vulnerability in Mozilla Firefox

Type Confusion
CVE-2019-11707

The vulnerability was reported by Mozilla to be actively exploited in the wild.

This vulnerability as reportedly used in a targeted attack against Coinbase employees on Monday,  June 17 2019.

The vulnerability was used in conjunction with another sandbox bypass issue CVE-2019-11708, patched by Mozilla on June 20, 2019.

This vulnerability was  independently discovered and reported to Mozilla by a security researcher Samuel Gro├Я on April 15. It took Mozilla 64 days to issue a security fix. 


Vulnerability details

Advisory: SB2019061805 - Remote code execution in Mozilla Firefox and Firefox ESR

Vulnerable component: Mozilla Firefox

CVE-ID: CVE-2019-11707

CVSSv3 score: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-843 - Access of Resource Using Incompatible Type ('Type Confusion')

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).