CVE-2020-8621

Attempting QNAME minimization after forwarding can lead to an assertion failure in resolver.c

Description

In BIND 9.14.0 -> 9.16.5, 9.17.0 -> 9.17.3, If a server is configured with both QNAME minimization and 'forward first' then an attacker who can send queries to it may be able to trigger the condition that will cause the server to crash. Servers that 'forward only' are not affected.

Remediation

Solution:

  • Upgrade to the patched release most closely related to your current version of BIND: BIND 9.16.6 BIND 9.17.4

Workaround:

  • No workarounds known.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 1.98% Top 20%
Vendor Advisory ubuntu.com Vendor Advisory gentoo.org Vendor Advisory opensuse.org Vendor Advisory opensuse.org Vendor Advisory isc.org
Affected: ISC BIND9
Published at:
Updated at:

References

Link Tags
https://kb.isc.org/docs/cve-2020-8621 vendor advisory
https://security.netapp.com/advisory/ntap-20200827-0003/ third party advisory
https://usn.ubuntu.com/4468-1/ third party advisory vendor advisory
https://security.gentoo.org/glsa/202008-19 third party advisory vendor advisory
https://www.synology.com/security/advisory/Synology_SA_20_19 third party advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html mailing list third party advisory vendor advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html mailing list third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-8621?
CVE-2020-8621 has been scored as a high severity vulnerability.
How to fix CVE-2020-8621?
To fix CVE-2020-8621: Upgrade to the patched release most closely related to your current version of BIND: BIND 9.16.6 BIND 9.17.4
Is CVE-2020-8621 being actively exploited in the wild?
It is possible that CVE-2020-8621 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-8621?
CVE-2020-8621 affects ISC BIND9.
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