CVE-2019-19521 json
libc in OpenBSD 6.6 allows authentication bypass via the -schallenge username, as demonstrated by smtpd, ldapd, or radiusd.
published 2019-12-04 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-9139
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.7%
- EPSS 2.7% chance of exploitation in 30 days, percentile 86%
- public exploits
- 0
- none known
Summary
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).
Exploit prediction
2.74% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- openwall.com https://www.openwall.com/lists/oss-security/2019/12/04/5 referenced PoC, tagged "exploit" by a source, unverified
- openwall.com http://www.openwall.com/lists/oss-security/2019/12/04/5 referenced PoC, tagged "exploit" by a source, unverified
- seclists.org https://seclists.org/bugtraq/2019/Dec/8 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
openwall.com
/lists/oss-security/2019/12/04/5
exploit, mailing-list, third-party-advisory
-
openwall.com
/lists/oss-security/2019/12/04/5
mailing-list, exploit, third-party-advisory
-
seclists.org
/bugtraq/2019/Dec/8
mailing-list, exploit, third-party-advisory
-
openbsd.org
/errata66.html
vendor-advisory
-
openwall.com
/lists/oss-security/2019/12/04/6
mailing-list
-
packetstormsecurity.com
/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html
third-party-advisory
-
seclists.org
/fulldisclosure/2019/Dec/14
mailing-list, third-party-advisory
Sources
- CVE List CVE-2019-19521
- NVD CVE-2019-19521
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