Auth bypass in OpenBSD
CVE-2019-19521
libc in OpenBSD 6.6 allows authentication bypass via the -schallenge username, as demonstrated by smtpd, ldapd, or radiusd. This is related to gen/auth_subr.c and gen/authenticate.c in libc (and login/login.c and xenocara/app/xenodm/greeter/verify.c).
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.027 (85.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.027 · newest: 0.027 · change: 0.000
Affected products
- OpenBSD — versions 6.6
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.openwall.com/lists/oss-security/2019/12/04/5 (Exploit, Mailing List, Third Party Advisory)
- www.openbsd.org/errata66.html (Vendor Advisory)
- www.openwall.com/lists/oss-security/2019/12/04/6 (mailing-list, Mailing List)
- www.openwall.com/lists/oss-security/2019/12/04/5 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- seclists.org/bugtraq/2019/Dec/8 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentic… (Third Party Advisory)
- seclists.org/fulldisclosure/2019/Dec/14 (mailing-list, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-19521?
- CVE-2019-19521 is a critical-severity vulnerability in OpenBSD, classified under Improper Authentication. CVSS score: 9.8/10. Published 2019-12-05.
- How severe is CVE-2019-19521?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2019-19521 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.