Vulnerability in OpenBSD Libressl

CVE-2018-8970

The int_x509_param_set_hosts function in lib/libcrypto/x509/x509_vpm.c in LibreSSL 2.7.0 before 2.7.1 does not support a certain special case of a zero name length, which causes silent omission of hostname verification, and consequently allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate. NOTE: the LibreSSL documentation indicates that this special case is supported, but the BoringSSL documentation does not.

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.010 (62.0th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2018-8970: held from 0.010 to 0.010.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: -0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-8970?
CVE-2018-8970 is a high-severity vulnerability in OpenBSD Libressl, classified under Improper Certificate Validation. CVSS score: 7.4/10. Published 2018-03-24.
How severe is CVE-2018-8970?
High severity. CVSS v3 base score is 7.4 out of 10.
Is CVE-2018-8970 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.