1) Type Confusion

Severity: Critical

CVSSv3: 8.4 [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] [PCI]

CVE-ID: CVE-2019-11707

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).

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Firefox ESR: 60.0, 60.0.1, 60.0.2, 60.1.0, 60.2.0, 60.2.1, 60.2.2, 60.3.0, 60.4.0, 60.5.0, 60.5.1, 60.5.2, 60.6.0, 60.6.1, 60.6.2, 60.6.3, 60.7.0

Mozilla Firefox: 61.0, 61.0.1, 61.0.2, 62.0, 62.0.1, 62.0.2, 62.0.3, 63.0, 63.0.1, 63.0.3, 64.0, 64.0.1, 64.0.2, 65.0, 65.0.1, 65.0.2, 66.0, 66.0.1, 66.0.2, 66.0.3, 66.0.4, 66.0.5, 67.0, 67.0.1, 67.0.2

CPE

• cpe:/a:mozilla:firefox_esr:60.7.0:
• cpe:/a:mozilla:firefox_esr:60.6.3:
• cpe:/a:mozilla:firefox_esr:60.6.2:
• cpe:/a:mozilla:firefox_esr:60.6.1:
• cpe:/a:mozilla:firefox_esr:60.6.0:
• cpe:/a:mozilla:firefox_esr:60.5.2:
• cpe:/a:mozilla:firefox_esr:60.3.0:
• cpe:/a:mozilla:firefox_esr:60.0.2:
• cpe:/a:mozilla:firefox_esr:60.0.1:
• cpe:/a:mozilla:firefox_esr:60.5.1:
• cpe:/a:mozilla:firefox_esr:60.5.0:
• cpe:/a:mozilla:firefox_esr:60.4.0:
• cpe:/a:mozilla:firefox_esr:60.2.2:
• cpe:/a:mozilla:firefox_esr:60.2.1:
• cpe:/a:mozilla:firefox_esr:60.2.0:
• cpe:/a:mozilla:firefox_esr:60.1.0:
• cpe:/a:mozilla:firefox_esr:60.0:
• cpe:/a:mozilla:mozilla_firefox:67.0.2:
• cpe:/a:mozilla:mozilla_firefox:67.0.1:
• cpe:/a:mozilla:mozilla_firefox:67.0:
• cpe:/a:mozilla:mozilla_firefox:66.0.5:
• cpe:/a:mozilla:mozilla_firefox:66.0.4:
• cpe:/a:mozilla:mozilla_firefox:66.0.3:
• cpe:/a:mozilla:mozilla_firefox:66.0.2:
• cpe:/a:mozilla:mozilla_firefox:66.0.1:
• cpe:/a:mozilla:mozilla_firefox:66.0:
• cpe:/a:mozilla:mozilla_firefox:65.0.2:
• cpe:/a:mozilla:mozilla_firefox:65.0.1:
• cpe:/a:mozilla:mozilla_firefox:65.0:
• cpe:/a:mozilla:mozilla_firefox:64.0.2:
• cpe:/a:mozilla:mozilla_firefox:64.0.1:
• cpe:/a:mozilla:mozilla_firefox:64.0:
• cpe:/a:mozilla:mozilla_firefox:63.0.3:
• cpe:/a:mozilla:mozilla_firefox:63.0.1:
• cpe:/a:mozilla:mozilla_firefox:63.0:
• cpe:/a:mozilla:mozilla_firefox:62.0.3:
• cpe:/a:mozilla:mozilla_firefox:62.0.2:
• cpe:/a:mozilla:mozilla_firefox:62.0.1:
• cpe:/a:mozilla:mozilla_firefox:62.0:
• cpe:/a:mozilla:mozilla_firefox:61.0.2:
• cpe:/a:mozilla:mozilla_firefox:61.0.1:
• cpe:/a:mozilla:mozilla_firefox:61.0:

External links

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