Zero-day vulnerability in Mozilla Firefox

Type Confusion
CVE-2019-17026

The vulnerability was reported by Qihoo 360 ATA researchers.

Vulnerability details

Advisory: SB2020010819 - Remote code execution in Mozilla Firefox and Firefox ESR

Vulnerable component: Mozilla Firefox

CVE-ID: CVE-2019-17026

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 with StoreElementHole and FallibleStoreElement when processing HTML content in IonMonkey JIT compiler. A remote attacker can create a specially crafted webpage, 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.

Public Exploits:

- Firefox 72 IonMonkey - JIT Type Confusion [Exploit-DB]

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

External links:

https://www.mozilla.org/en-US/security/advisories/mfsa2020-03/


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.