#VU24061 Algorithm Downgrade in Mozilla Firefox


Published: 2020-01-07 | Updated: 2020-01-08

Vulnerability identifier: #VU24061

Vulnerability risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-17023

CWE-ID: CWE-757

Exploitation vector: Network

Exploit availability: No

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

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to bypass certain security restrictions.

The vulnerability exists due to insecure negotiation After a HelloRetryRequest in Mozilla NSS that can lead to selection of a less secure protocol (e.g. TLS 1.2 or below) after the HelloRetryRequest TLS 1.3 is sent.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 65.0 - 71.0


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


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