What is CVE-2016-4456?

CVE-2016-4456 is a high-severity vulnerability in GNU Gnutls, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2017-08-08.

How severe is CVE-2016-4456?

High severity. CVSS v3 base score is 7.5 out of 10.

Improper input validation in GNU Gnutls

CVE-2016-4456

The "GNUTLS_KEYLOGFILE" environment variable in gnutls 3.4.12 allows remote attackers to overwrite and corrupt arbitrary files in the filesystem.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2017-08-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.022 (81.8th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000

Affected products

GNU Gnutls — versions 3.4.12

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
www.openwall.com/lists/oss-security/2016/06/07/6 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2016-4456?: CVE-2016-4456 is a high-severity vulnerability in GNU Gnutls, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2017-08-08.
How severe is CVE-2016-4456?: High severity. CVSS v3 base score is 7.5 out of 10.