CVE-2020-24659

Name: CVE-2020-24659
Creator: NVD / NIST
Published: 2020-09-04T15:15:10.803+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 3.73%

Last modified Jun 17, 2026

CVE-2020-24659 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. EPSS estimates a 3.73% chance of exploitation in the next 30 days.

Description

An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

3.73%

88.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gnu	Gnutls	< 3.6.15
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Opensuse	Leap	15.1
Opensuse	Leap	15.2
Canonical	Ubuntu Linux	20.04

References

http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00054.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00060.htmlMailing List, Third Party Advisory
https://gitlab.com/gnutls/gnutls/-/issues/1071Exploit, Issue Tracking, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/62BUAI4FQQLG6VTKRT7SUZPGJJ4NASQ3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AWN56FDLQQXT2D2YHNI4TYH432TDMQ7N/
https://security.gentoo.org/glsa/202009-01Third Party Advisory
https://security.netapp.com/advisory/ntap-20200911-0006/Third Party Advisory
https://usn.ubuntu.com/4491-1/Third Party Advisory
https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-09-04Vendor Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00054.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00060.htmlMailing List, Third Party Advisory
https://gitlab.com/gnutls/gnutls/-/issues/1071Exploit, Issue Tracking, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/62BUAI4FQQLG6VTKRT7SUZPGJJ4NASQ3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AWN56FDLQQXT2D2YHNI4TYH432TDMQ7N/
https://security.gentoo.org/glsa/202009-01Third Party Advisory
https://security.netapp.com/advisory/ntap-20200911-0006/Third Party Advisory
https://usn.ubuntu.com/4491-1/Third Party Advisory
https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-09-04Vendor Advisory

Timeline

Published: Sep 4, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-24659?

How severe is CVE-2020-24659?

CVE-2020-24659 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 3.73% probability of exploitation in the next 30 days.

How do I fix CVE-2020-24659?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-24659?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST