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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.035 (88.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 88.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.035 · newest: 0.035 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.openbsd.org/errata66.html (Patch, Vendor Advisory)
- www.openwall.com/lists/oss-security/2019/12/11/9 (Mailing List, Third Party Advisory)
- seclists.org/bugtraq/2019/Dec/25 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- packetstormsecurity.com/files/155658/Qualys-Security-Advisory-OpenBSD-Dynamic-L… (Exploit, VDB Entry, Third Party Advisory)
- seclists.org/fulldisclosure/2019/Dec/31 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- packetstormsecurity.com/files/155764/OpenBSD-Dynamic-Loader-chpass-Privilege-Es… (VDB Entry, Third Party Advisory)
- www.openwall.com/lists/oss-security/2023/10/03/2 (mailing-list)
- seclists.org/fulldisclosure/2023/Oct/11 (mailing-list)
- packetstormsecurity.com/files/174986/glibc-ld.so-Local-Privilege-Escalation.html
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.