#VU48462 Universal cross-site scripting


Published: 2020-11-17

Vulnerability identifier: #VU48462

Vulnerability risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26956

CWE-ID: CWE-79

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 disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data. In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

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