Vulnerability identifier: #VU18039

Vulnerability risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-9801

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to Firefox accepts any registered Program ID as an external protocol handler and offer to launch this local application when given a matching URL on Windows operating systems. A remote attacker can trick the victim to open a specially crafted link and execute an arbitrary application on the system with privileges of the current user.

Note: this vulnerability affects Windows operating system only.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 61.0 - 65.0.2

---

External links
http://www.mozilla.org/en-US/security/advisories/mfsa2019-07/
http://bugzilla.mozilla.org/show_bug.cgi?id=1527717

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.