CVE-2019-19521

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-12-05 · updated 2026-06-17
Weakness: CWE-287

Description

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).

Affected products

OpenBSD: 6.6

References

http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html
http://seclists.org/fulldisclosure/2019/Dec/14
http://www.openwall.com/lists/oss-security/2019/12/04/5
http://www.openwall.com/lists/oss-security/2019/12/04/6
https://seclists.org/bugtraq/2019/Dec/8
https://www.openbsd.org/errata66.html
https://www.openwall.com/lists/oss-security/2019/12/04/5
http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html
http://seclists.org/fulldisclosure/2019/Dec/14
http://www.openwall.com/lists/oss-security/2019/12/04/5
http://www.openwall.com/lists/oss-security/2019/12/04/6
https://seclists.org/bugtraq/2019/Dec/8

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