TI-2019-14063 Aliases CVE-2019-19521 GHSA-gw7q-976q-g767

libc in OpenBSD 6.6 allows authentication bypass via the -schallenge username, as…

MEDIUM 47CWE-287Published 2019-12-04 · Updated 2024-08-05

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-287.

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).

Why it matters now

EPSS 0.02736 86th percentileScored 2026-11-07

Public exploit Yes 3 exploit referencesTagged by NVD

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:o:openbsd:openbsd:6.6:::::::*	6.6	Vulnerable	OpenBSD

cpe:2.3:o:openbsd:openbsd:6.6:*:*:*:*:*:*:* Versions 6.6 Vulnerable ·OpenBSD

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2019-19521
2026-10-03 Alias added: GHSA-gw7q-976q-g767

References

Exploit 3

Advisory 3

Other 1

[oss-security] 20191204 Re: Authentication vulnerabilities in OpenBSD

TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
TI-2007-05153 Stack-based buffer overflow in the cons_options function in options.c in dhcpd in OpenBSD… CVSS 2.0HIGH 7.2
TI-2001-00539 Buffer overflow in BSD-based telnetd telnet daemon on various operating systems allows… CVSS 2.0HIGH 10.0
TI-2026-40218 sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows authentication… CVSS 3.1HIGH 8.3
TI-2004-00444 Heap-based buffer overflow in proxy_util.c for mod_proxy in Apache 1.3.25 to 1.3.31… CVSS 2.0HIGH 10.0

See all 200 →

Sources

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