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Fencer Intel
high 7.8

CVE-2019-19726 json

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 settin…

published 6y ago modified 4mo ago also EUVD-2019-9328

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.5%
EPSS 3.5% chance of exploitation in 30 days, percentile 89%
public exploits
3
Metasploit and Exploit-DB

Summary

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.

Patch / fix

Is CVE-2019-19726 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Timeline

  1. First public exploit (Metasploit exploit/openbsd/local/dynamic_loader_chpass_privesc)
  2. Published

Exploit prediction

3.52% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Metasploit exploit/openbsd/local/dynamic_loader_chpass_privesc OpenBSD Dynamic Loader chpass Privilege Escalation metasploit exploit, excellent rank, 2019-12-11
  • EDB-47803 OpenBSD - Dynamic Loader chpass Privilege Escalation (Metasploit) local, 2019-12-30
  • EDB-47780 OpenBSD 6.x - Dynamic Loader Privilege Escalation local, 2019-12-16
  • seclists.org https://seclists.org/bugtraq/2019/Dec/25 referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/155658/Qualys-Security-Advisory-OpenBSD-Dynamic-Loader-Privilege-Escalation.html referenced PoC, tagged "exploit" by a source, unverified
  • seclists.org http://seclists.org/fulldisclosure/2019/Dec/31 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-269 Improper Privilege Management

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.