Vulnerability identifier: #VU46015

Vulnerability risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15663

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

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

Vendor: Mozilla

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due Mozilla Maintenance Service does not check if the updater.exe file has a valid signature before executing it with elevated privileges. A local user with ability to replace the updater.exe file file can execute arbitrary code with SYSTEM privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Firefox ESR: 78.0 - 78.1.0, 68.0 - 68.11.0, 60.0 - 60.9.0

Mozilla Firefox: 7.0.1 - 79.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2020-38/
http://www.mozilla.org/en-US/security/advisories/mfsa2020-37/
http://www.mozilla.org/en-US/security/advisories/mfsa2020-36/

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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