CVE-2020-8623: A flaw in native PKCS#11 code can lead to a remotely triggerable assertion failure in pk11.c

Published Aug 21, 2020
·
Updated

In BIND 9.10.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.10.5-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker that can reach a vulnerable system with a specially crafted query packet can trigger a crash. To be vulnerable, the system must: be running BIND that was built with "--enable-native-pkcs11" be signing one or more zones with an RSA key be able to receive queries from a possible attacker

Affected Software

17 affected componentsFixes available
ISC BIND>=9.10.0<=9.11.21
ISC BIND>=9.12.1<=9.16.5
ISC BIND>=9.17.0<=9.17.3
ISC BIND=9.10.5-s1
ISC BIND=9.11.21-s1
Fedoraproject Fedora=31
Fedoraproject Fedora=32
openSUSE Leap=15.1
openSUSE Leap=15.2
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=20.04
Synology DNS Server<2.2.2-5027
NetApp Steelstore Cloud Integrated Storage
debian/bind9
1:9.16.50-1~deb11u21:9.16.50-1~deb11u41:9.18.41-1~deb12u11:9.18.44-1~deb12u11:9.20.18-1~deb13u11:9.20.20-1

Remediation

Information

Upgrade to the patched release most closely related to your current version of BIND: BIND 9.11.22 BIND 9.16.6 BIND 9.17.4 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.22-S1

Event History

Aug 21, 2020
CVE Published
via MITRE·08:50 PM
Data Sourced
via MITRE·08:50 PM
RemedyDescriptionSeverityWeakness
Feb 24, 2026
Data Sourced
via Ubuntu·12:53 AM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Launchpad·12:54 AM
Description
Mar 15, 2026
Data Sourced
via Debian·01:11 AM
DescriptionAffected Software
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is CVE-2020-8623?

CVE-2020-8623 is a vulnerability in BIND DNS software that allows an attacker to crash a vulnerable system with a specially crafted query packet.

2

Which versions of BIND are affected by CVE-2020-8623?

BIND versions 9.10.0 to 9.11.21, 9.12.0 to 9.16.5, and 9.17.0 to 9.17.3 are affected by CVE-2020-8623.

3

How can an attacker exploit the CVE-2020-8623 vulnerability?

An attacker can exploit the CVE-2020-8623 vulnerability by sending a specially crafted query packet to a vulnerable BIND DNS server.

4

What is the severity of CVE-2020-8623?

CVE-2020-8623 has a severity score of 7.5 (High).

5

Are there any references for CVE-2020-8623?

Yes, you can find references for CVE-2020-8623 at the following links: [Link 1](https://kb.isc.org/docs/cve-2020-8623), [Link 2](https://gitlab.isc.org/isc-projects/bind9/commit/ac3862a5da95bb07b6cf748b0958175687a9de1d), [Link 3](https://gitlab.isc.org/isc-projects/bind9/commit/8d807cc21655eaa6e6a08afafeec3682c0f3f2ab).

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203