Vulnerability identifier: #VU49015

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-2020-26973

CWE-ID: CWE-20

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 bypass implemented security restrictions.

The vulnerability exists due to insufficient validation of user-supplied input within CSS Sanitizer. A remote attacker can create a specially crafted web page, trick the victim into visiting it, and bypass implemented security restrictions.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 60.0 - 83.0

Firefox ESR: 78.0 - 78.5.0, 68.0 - 68.12.0, 60.0 - 60.9.0

---

External links
http://www.mozilla.org/en-US/security/advisories/mfsa2020-54/
http://www.mozilla.org/en-US/security/advisories/mfsa2020-55/

---

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.