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:3.1/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 - 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).

Public Exploits:

- Mozilla Firefox 67 - Array.pop JIT Type Confusion [Exploit-DB]

External links:

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.