#VU27530 Permissions, Privileges, and Access Controls in Mozilla Firefox and Firefox ESR - CVE-2020-12388

Vulnerability identifier: #VU27530

Vulnerability risk: High

CVSSv4.0: 7.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2020-12388

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: Yes

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

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to bypass sandbox restrictions.

The vulnerability exists due the Firefox content processes did not sufficiently lockdown access control due to improper protection of access tokens. A remote attacker can bypass implemented security restrictions and execute arbitrary code on the target system.

Note, this vulnerability affects Windows versions only.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 60.0 - 75.0

Firefox ESR: 60.0 - 60.9.0, 68.0 - 68.7.0

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2020-16/
https://www.mozilla.org/en-US/security/advisories/mfsa2020-17/
https://bugzilla.mozilla.org/show_bug.cgi?id=1618911

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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. However, proof of concept for this vulnerability is available.