Description
A malicious actor who intentionally exploits this lack of effective limitation on the number of fetches performed when processing referrals can, through the use of specially crafted referrals, cause a recursing server to issue a very large number of fetches in an attempt to process the referral. This has at least two potential effects: The performance of the recursing server can potentially be degraded by the additional work required to perform these fetches, and The attacker can exploit this behavior to use the recursing server as a reflector in a reflection attack with a high amplification factor.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ISC | BIND9 | 9.0.0 -> 9.11.18, 9.12.0 -> 9.12.4-P2, 9.14.0 -> 9.14.11, 9.16.0 -> 9.16.2, and releases 9.17.0 -> 9.17.1 of the 9.17 experimental development branch. All releases in the obsolete 9.13 and 9.15 development branches. All releases of BIND Supported Preview Edition from 9.9.3-S1 -> 9.11.18-S1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | bind9 | 1:9.16.3-1 | — |
| Debian 13 | bind9 | 1:9.16.3-1 | — |
| Debian 12 | bind9 | 1:9.16.3-1 | — |
| Debian 10 | bind9 | 1:9.11.5.P4+dfsg-5.1+deb10u1 | DSA-4689-1 |
| Debian 9 | bind9 | 1:9.10.3.dfsg.P4-12.3+deb9u6 | DSA-4689-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 8 | bind9 | 1:9.9.5.dfsg-9+deb8u19 | DLA-2227-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | bind9 | 1:9.16.1-0ubuntu2.1 | USN-4365-1 |
| Ubuntu 18.04 LTS | bind9 | 1:9.11.3+dfsg-1ubuntu1.12 | USN-4365-1 |
| Ubuntu 16.04 LTS | bind9 | 1:9.10.3.dfsg.P4-8ubuntu1.16 | USN-4365-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | bind9 | 1:9.9.5.dfsg-3ubuntu0.19+esm2 | USN-4365-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | bind +16 | 32:9.11.13-5.el8_2 | RHSA-2020:2338 |
| RHEL 7 | bind +15 | 32:9.11.4-16.P2.el7_8.6 | RHSA-2020:2344 |
| RHEL 6 | bind +5 | 32:9.8.2-0.68.rc1.el6_10.7 | RHSA-2020:2383 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.1 EUS | bind +16 | 32:9.11.4-26.P2.el8_1.3 | RHSA-2020:2345 |
| RHEL 8.0 E4S | bind +16 | 32:9.11.4-19.P2.el8_0 | RHSA-2020:2404 |
| RHEL 7.7 EUS | bind +15 | 32:9.11.4-9.P2.el7_7.2 | RHSA-2020:3272 |
| RHEL 7.6 EUS | bind +13 | 32:9.9.4-74.el7_6.4 | RHSA-2020:3475 |
| RHEL 7.4 TUS | bind +13 | 32:9.9.4-51.el7_4.4 | RHSA-2020:3433 |
| RHEL 7.4 E4S | bind +13 | 32:9.9.4-51.el7_4.4 | RHSA-2020:3433 |
| RHEL 7.4 AUS | bind +13 | 32:9.9.4-51.el7_4.4 | RHSA-2020:3433 |
| RHEL 7.3 TUS | bind +13 | 32:9.9.4-50.el7_3.4 | RHSA-2020:3470 |
| RHEL 7.3 E4S | bind +13 | 32:9.9.4-50.el7_3.4 | RHSA-2020:3470 |
| RHEL 7.3 AUS | bind +13 | 32:9.9.4-50.el7_3.4 | RHSA-2020:3470 |
| RHEL 7.2 AUS | bind +13 | 32:9.9.4-29.el7_2.9 | RHSA-2020:3471 |
| RHEL 6.6 AUS | bind +5 | 32:9.8.2-0.30.rc1.el6_6.11 | RHSA-2020:3378 |
| RHEL 6.5 AUS | bind +5 | 32:9.8.2-0.23.rc1.el6_5.9 | RHSA-2020:3379 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | bind | 9.16.6-12.32.1 | SUSE-SU-2020:2914-1 |
| SLES 15 SP2 | sysuser-tools | 2.0-4.2.8 | SUSE-SU-2020:2914-1 |
| SLES 15 SP1 | bind | 9.16.6-12.32.1 | SUSE-SU-2020:2914-1 |
| SLES 15 SP1 | sysuser-tools | 2.0-4.2.8 | SUSE-SU-2020:2914-1 |
| SLES 15 | bind | 9.16.6-12.32.1 | SUSE-SU-2020:2914-1 |
| SLES 15 | sysuser-tools | 2.0-4.2.8 | SUSE-SU-2020:2914-1 |
| SLES 12 SP5 | bind | 9.11.2-3.17.1 | SUSE-SU-2020:1350-1 |
| SLES 12 SP4 | bind | 9.11.2-3.17.1 | SUSE-SU-2020:1350-1 |
Show 15 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SLES 12 SP2 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SLES 11 SP4 | bind | 9.9.6P1-0.51.20.1 | SUSE-SU-2020:14400-1 |
| SLES for SAP 15 | bind | 9.16.6-12.32.1 | SUSE-SU-2020:2914-1 |
| SLES for SAP 15 | sysuser-tools | 2.0-4.2.8 | SUSE-SU-2020:2914-1 |
| SLES for SAP 12 SP5 | bind | 9.11.2-3.17.1 | SUSE-SU-2020:1350-1 |
| SLES for SAP 12 SP4 | bind | 9.11.2-3.17.1 | SUSE-SU-2020:1350-1 |
| SLES for SAP 12 SP3 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SLES for SAP 12 SP2 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SLE HPC 15 | bind | 9.16.6-12.32.1 | SUSE-SU-2020:2914-1 |
| SLE HPC 15 | sysuser-tools | 2.0-4.2.8 | SUSE-SU-2020:2914-1 |
| SUSE OpenStack Cloud Crowbar 8 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SUSE OpenStack Cloud 8 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SUSE OpenStack Cloud 7 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | bind | 9.9.6P1-0.51.20.1 | SUSE-SU-2020:14400-1 |
| SUSE HPE Helion OpenStack 8 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
| SUSE Enterprise Storage 5 | bind | 9.9.9P1-63.17.1 | SUSE-SU-2020:1914-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | bind | 9.16.20-1.4 | openSUSE-SU-2024:10650-1 |
| openSUSE Leap 15.2 | bind | 9.16.6-lp152.14.3.1 | openSUSE-SU-2020:1699-1 |
| openSUSE Leap 15.2 | libuv | 1.18.0-lp152.4.3.1 | openSUSE-SU-2020:1699-1 |
| openSUSE Leap 15.2 | sysuser-tools | 2.0-lp152.5.3.1 | openSUSE-SU-2020:1699-1 |
| openSUSE Leap 15.1 | bind | 9.16.6-lp151.11.9.1 | openSUSE-SU-2020:1701-1 |
| openSUSE Leap 15.1 | libuv | 1.18.0-lp151.3.3.1 | openSUSE-SU-2020:1701-1 |
| openSUSE Leap 15.1 | sysuser-tools | 2.0-lp151.4.3.1 | openSUSE-SU-2020:1701-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | bind | 9.14.12-r0 | — |
| Alpine v3.23 | bind | 9.14.12-r0 | — |
| Alpine v3.22 | bind | 9.14.12-r0 | — |
| Alpine v3.21 | bind | 9.14.12-r0 | — |
| Alpine v3.20 | bind | 9.14.12-r0 | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | bind | 9.14.12-r0 | — |
| Alpine v3.18 | bind | 9.14.12-r0 | — |
| Alpine v3.17 | bind | 9.14.12-r0 | — |
| Alpine v3.16 | bind | 9.14.12-r0 | — |
| Alpine v3.15 | bind | 9.14.12-r0 | — |
| Alpine v3.14 | bind | 9.14.12-r0 | — |
| Alpine v3.13 | bind | 9.14.12-r0 | — |
| Alpine v3.12 | bind | 9.14.12-r0 | — |
| Alpine v3.11 | bind | 9.14.12-r0 | — |
| Alpine v3.10 | bind | 9.14.12-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | bind +15 | 32:9.11.4-9.P2.amzn2.0.3 | ALAS2-2020-1426 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | bind +16 | 32:9.11.13-5.el8_2 | ELSA-2020-2338 |
| Oracle Linux 7 | bind +15 | 32:9.11.4-16.P2.el7_8.6 | ELSA-2020-2344 |
Advisories 28
- RHSA-2020:3470 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3433 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3475 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3272 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:2345 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:2383 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:2404 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:2338 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3471 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3378 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3379 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:2344 Red Hat Security Advisory: bind security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- WID-SEC-2025-1198 Internet Systems Consortium BIND: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Apr 27, 2026
- USN-4365-2 bind9 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4365-1 bind9 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4689-1 bind9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2227-1 bind9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:2914-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1914-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1699-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1350-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10650-1 bind-9.16.20-1.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1701-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:14400-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-0978 Mehrere DNS Server: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Oct 1, 2024
- ELSA-2020-2338 Important: bind security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jun 4, 2020
- ELSA-2020-2344 Important: bind security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 1, 2020
- ALAS2-2020-1426 Important: bind security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · May 20, 2020
References
- https://kb.isc.org/docs/cve-2020-8616
- http://www.nxnsattack.com
- [oss-security] 20200519 Two vulnerabilities disclosed in BIND (CVE-2020-8616 and CVE-2020-8617) mailing-list
- DSA-4689 vendor-advisory
- https://security.netapp.com/advisory/ntap-20200522-0002/
- USN-4365-2 vendor-advisory
- https://www.synology.com/security/advisory/Synology_SA_20_12
- USN-4365-1 vendor-advisory
- [debian-lts-announce] 20200530 [SECURITY] [DLA 2227-1] bind9 security update mailing-list
- FEDORA-2020-2d89cbcfd9 vendor-advisory
- FEDORA-2020-f9dcd4e9d5 vendor-advisory
- openSUSE-SU-2020:1699 vendor-advisory
- openSUSE-SU-2020:1701 vendor-advisory