PT-2020-6021 · Isc+4 · Bind+4

Joseph Gullo · Published 2020-08-20 · Updated 2024-06-15 · CVE-2020-8621

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

Name of the Vulnerable Software and Affected Versions BIND versions 9.14.0 through 9.16.5 BIND versions 9.17.0 through 9.17.3

Description The issue arises when a server is configured with both QNAME minimization and 'forward first'. An attacker who can send queries to the server may be able to trigger a condition that causes the server to crash. This does not affect servers that 'forward only'. The vulnerability is due to insufficient input validation, which can be exploited by a remote attacker to cause a denial of service.

Recommendations For BIND versions 9.14.0 through 9.16.5, consider disabling QNAME minimization when 'forward first' is configured to prevent the server from crashing. For BIND versions 9.17.0 through 9.17.3, consider disabling QNAME minimization when 'forward first' is configured to prevent the server from crashing. As a temporary workaround, consider restricting the 'forward first' configuration to minimize the risk of exploitation.

Exploit

Fix

Assertion Failure

RCE

Weakness Enumeration

CWE-617

CWE-20

Related Identifiers

BDU:2021-02673

CVE-2020-8621

OPENSUSE-SU-2020:1699-1

OPENSUSE-SU-2020:1701-1

OPENSUSE-SU-2020_1699-1

OPENSUSE-SU-2020_1701-1

OPENSUSE-SU-2024:10650-1

SUSE-SU-2020:2914-1

USN-4468-1

Affected Products

Bind

Bind Server

Linuxmint

Suse

Ubuntu

References · 88

• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/dos/dns/bind_tsig_badtime.rb · Exploit
• 🔥 https://github.com/knqyf263/CVE-2020-8617 · Exploit
• https://osv.dev/vulnerability/openSUSE-SU-2020:1699-1 · Vendor Advisory
• https://osv.dev/vulnerability/USN-4468-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-8622 · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2020-8621 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-8621 · Security Note
• https://usn.ubuntu.com/4468-1 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2020-8621 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-8620 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2020:1701-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2020:2914-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2020-8621 · Vendor Advisory
• https://security.gentoo.org/glsa/202008-19 · Vendor Advisory