#VU48463 Permissions, Privileges, and Access Controls


Published: 2020-11-17

Vulnerability identifier: #VU48463

Vulnerability risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26958

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

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 escalate privileges on the system.

The vulnerability exists due Firefox does not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. A remote attacker can exploit this behavior to perform a cross-site script inclusion vulnerability or bypass implemented Content Security Policy restrictions.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 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, 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, 67.0.3, 67.0.4, 68.0, 68.0.1, 68.0.2, 69.0, 69.0.1, 69.0.2, 69.0.3, 70.0, 70.0.1, 71.0, 72.0, 72.0.1, 72.0.2, 73.0, 73.0.1, 74.0, 74.0.1, 75.0, 76.0, 76.0.1, 77.0, 77.0.1, 78.0, 78.0.1, 78.0.2, 79.0, 80.0, 80.0.1, 81.0, 81.0.1, 81.0.2, 82.0, 82.0.1, 82.0.2, 82.0.3

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, 60.7.1, 60.7.2, 60.8.0, 60.9.0, 68.0, 68.0.1, 68.0.2, 68.1.0, 68.2.0, 68.3.0, 68.4.0, 68.4.1, 68.4.2, 68.5.0, 68.6.0, 68.6.1, 68.7.0, 68.8.0, 68.9.0, 68.10.0, 68.11.0, 68.12.0, 78.0, 78.0.1, 78.0.2, 78.1.0, 78.2.0, 78.3.0, 78.3.1, 78.4.0, 78.4.1

CPE

External links
https://www.mozilla.org/en-US/security/advisories/mfsa2020-50/
https://www.mozilla.org/en-US/security/advisories/mfsa2020-51/


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.


Latest bulletins with this vulnerability