CVE-2019-19726

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-12-12 · updated 2026-06-17
Weakness: CWE-269

Description

OpenBSD through 6.6 allows local users to escalate to root because a check for LD_LIBRARY_PATH in setuid programs can be defeated by setting a very small RLIMIT_DATA resource limit. When executing chpass or passwd (which are setuid root), _dl_setup_env in ld.so tries to strip LD_LIBRARY_PATH from the environment, but fails when it cannot allocate memory. Thus, the attacker is able to execute their own library code as root.

Affected products

OpenBSD: through 6.6

References

http://packetstormsecurity.com/files/155658/Qualys-Security-Advisory-OpenBSD-Dynamic-Loader-Privilege-Escalation.html
http://packetstormsecurity.com/files/155764/OpenBSD-Dynamic-Loader-chpass-Privilege-Escalation.html
http://packetstormsecurity.com/files/174986/glibc-ld.so-Local-Privilege-Escalation.html
http://seclists.org/fulldisclosure/2019/Dec/31
http://seclists.org/fulldisclosure/2023/Oct/11
http://www.openwall.com/lists/oss-security/2023/10/03/2
https://seclists.org/bugtraq/2019/Dec/25
https://www.openbsd.org/errata66.html
https://www.openwall.com/lists/oss-security/2019/12/11/9
http://packetstormsecurity.com/files/155658/Qualys-Security-Advisory-OpenBSD-Dynamic-Loader-Privilege-Escalation.html
http://packetstormsecurity.com/files/155764/OpenBSD-Dynamic-Loader-chpass-Privilege-Escalation.html
http://packetstormsecurity.com/files/174986/glibc-ld.so-Local-Privilege-Escalation.html

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