CVE-2019-17023 Security feature bypass in Firefox
A flaw in Firefox's TLS state machine allows attackers to cause the browser to ignore application data after a HelloRetryRequest, bypassing security expectations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2019-17023?
CVE-2019-17023 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 8 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
After a HelloRetryRequest has been sent, the client may negotiate a lower protocol that TLS 1.3, resulting in an invalid state transition in the TLS State Machine. If the client gets into this state, incoming Application Data records will be ignored. This vulnerability affects Firefox < 72.
Weakness: CWE-287
Which versions are affected by CVE-2019-17023?
It affects 3 products.
Products include Canonical Ubuntu Linux, Debian Debian Linux, Mozilla Firefox.
How do I fix CVE-2019-17023?
Upgrade to a fixed version.
Is CVE-2019-17023 being exploited?
There is no known exploitation of CVE-2019-17023 in the wild and no public exploit code.
Other vulnerabilities in Canonical Ubuntu Linux
Sources
Also known as ALPINE-CVE-2019-17023, DEBIAN-CVE-2019-17023, GHSA-86rq-87v9-7ppc, UBUNTU-CVE-2019-17023.