Vulnerability identifier: #VU24054

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-17016

CWE-ID: CWE-94

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 gain access to sensitive information.

The vulnerability exists due to improper input validation when pasting a tag from the clipboard into a rich text editor, the CSS sanitizer incorrectly rewrites a @namespace rule. This could allow for injection into certain types of websites resulting in data exfiltration.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 65.0 - 71.0

Firefox ESR: 68.0 - 68.3.0, 60.0 - 60.9.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2020-01/
http://www.mozilla.org/en-US/security/advisories/mfsa2020-02/

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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.