Zero-day vulnerability in Mozilla Firefox

Permissions, Privileges, and Access Controls
CVE-2019-11708

This vulnerability was used along with CVE-2019-11707 in a targeted attack against Conbase.

Vulnerability details

Advisory: SB2019062002 - Security restrictions bypass in Mozilla Firefox and Firefox ESR

Vulnerable component: Mozilla Firefox

CVE-ID: CVE-2019-11708

CVSSv3 score: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Description:

The vulnerability allows a remote attacker to bypass sandbox restrictions.

The vulnerability exists due to insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes. A remote attacker can create a specially crafted web page that can make the non-sandboxed parent process open web content chosen by a compromised child process.

An attacker can combine this behavior along with another vulnerability to execute arbitrary code on the system with privileges on the current user. 

Note, this vulnerability is being exploited in the wild along with SB2019061805 (CVE-2019-11707)

Public Exploits:

- Mozilla FireFox (Windows 10 x64) - Full Chain Client Side Attack [Exploit-DB]

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

External links:

https://twitter.com/5aelo/status/1141273396958900224

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.