Privilege escalation in Openbsd

CVE-2019-19726

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.

Vulnerability class: Privilege Escalation

EPSS: 0.035 (88.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-19726?
CVE-2019-19726 is a high-severity vulnerability in Openbsd, classified under Improper Privilege Management. CVSS score: 7.8/10. Published 2019-12-12.
How severe is CVE-2019-19726?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2019-19726 known to be exploited?
8 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.