Auth bypass in Mozilla Firefox
CVE-2019-17023
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.013 (70.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000
Affected products
- Mozilla Firefox — versions before 72
- Canonical Ubuntu Linux — versions 16.04, 18.04, 19.04
- Debian Linux — versions 10.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2020-01/ (Vendor Advisory)
- usn.ubuntu.com/4234-1/ (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4397-1/ (vendor-advisory, Third Party Advisory)
- www.debian.org/security/2020/dsa-4726 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-17023?
- CVE-2019-17023 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Authentication. CVSS score: 6.5/10. Published 2020-01-08.
- How severe is CVE-2019-17023?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2019-17023 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.