high 7.5

CVE-2020-8617 in the critical feed json

A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c

published 2020-05-19 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-29465

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 93.3%; EPSS 93.3% chance of exploitation in 30 days, percentile 99.8%
public exploits: 2; Metasploit, Exploit-DB

Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration does not otherwise make use of it, almost all current BIND servers are vulnerable. In releases of BIND dating from March 2018 and after, an assertion check in tsig.c detects this inconsistent state and deliberately exits. Prior to the introduction of the check the server would continue operating in an inconsistent state, with potentially harmful results.

Patch / fix

distros 7 links 2

debian ubuntu red hat suse opensuse alpine arch linux

bind9 Debian 14, Debian 13, Debian 12 1:9.16.3-1

debian advisories DEBIAN-CVE-2020-8617

bind9 Ubuntu 16.04 LTS 1:9.10.3.dfsg.P4-8ubuntu1.16
bind9 Ubuntu 18.04 LTS 1:9.11.3+dfsg-1ubuntu1.12
bind9 Ubuntu 20.04 LTS 1:9.16.1-0ubuntu2.1
bind9 Ubuntu Pro 14.04 LTS 1:9.9.5.dfsg-3ubuntu0.19+esm2

ubuntu advisories UBUNTU-CVE-2020-8617

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

bind RHEL 6 32:9.8.2-0.68.rc1.el6_10.7
bind-sdb RHEL 6 32:9.8.2-0.68.rc1.el6_10.7
bind-libs RHEL 6 32:9.8.2-0.68.rc1.el6_10.7
bind-utils RHEL 6 32:9.8.2-0.68.rc1.el6_10.7
bind-chroot RHEL 6 32:9.8.2-0.68.rc1.el6_10.7
bind RHEL 7 32:9.11.4-16.P2.el7_8.6
bind-sdb RHEL 7 32:9.11.4-16.P2.el7_8.6
bind-libs RHEL 7 32:9.11.4-16.P2.el7_8.6

red hat advisories RHSA-2020:3433 RHSA-2020:3379 RHSA-2020:3378 RHSA-2020:2893 RHSA-2020:2404 RHSA-2020:2383

bind SLES for SAP 15, SLES 15-LTSS, SLE Module for Server Applications 15 SP2 +5 more 9.16.6-12.32.1
sysuser-tools SLES for SAP 15, SLES 15-LTSS, SLE Module for Development Tools 15 SP2 +4 more 2.0-4.2.8
bind SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES 12 SP3-LTSS +8 more 9.9.9P1-63.17.1
bind SLES 11 SP4-LTSS, SLE Point of Sale 11 SP3 9.9.6P1-0.51.20.1
bind SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 9.11.2-3.17.1

suse advisories SUSE-SU-2020:2914-1 SUSE-SU-2020:1914-1 SUSE-SU-2020:14400-1 SUSE-SU-2020:1350-1

bind openSUSE Tumbleweed 9.16.20-1.4
bind openSUSE Leap 15.1 9.16.6-lp151.11.9.1
libuv openSUSE Leap 15.1 1.18.0-lp151.3.3.1
sysuser-tools openSUSE Leap 15.1 2.0-lp151.4.3.1
bind openSUSE Leap 15.2 9.16.6-lp152.14.3.1
libuv openSUSE Leap 15.2 1.18.0-lp152.4.3.1
sysuser-tools openSUSE Leap 15.2 2.0-lp152.5.3.1

opensuse advisories openSUSE-SU-2024:10650-1 openSUSE-SU-2020:1701-1 openSUSE-SU-2020:1699-1

bind Alpine 3.24, Alpine 3.23, Alpine 3.22 +12 more 9.14.12-r0

alpine advisories ALPINE-CVE-2020-8617

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

bind Arch Linux 9.16.3-1

arch linux advisories AVG-1165

kb.isc.org/docs/cve-2020-8617 advisory
openwall.com/lists/oss-security/2020/05/19/4 advisory

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-8617 updated 2026-11-07 cvss 7.5

bind: A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c

Red Hat Enterprise Linux 5 bind, bind97
affected: workaround, no fix planned “Out of support scope”
Red Hat Enterprise Linux AppStream (v. 8) bind 9.11.13-5.el8_2, bind-sdb 9.11.13-5.el8_2, bind-libs 9.11.13-5.el8_2, bind-utils 9.11.13-5.el8_2, bind-chroot 9.11.13-5.el8_2, bind-pkcs11 9.11.13-5.el8_2, +6 more
fixed: vendor fix RHSA-2020:2338
Red Hat Enterprise Linux AppStream E4S (v. 8.0) bind 9.11.4-19.P2.el8_0, bind-sdb 9.11.4-19.P2.el8_0, bind-libs 9.11.4-19.P2.el8_0, bind-utils 9.11.4-19.P2.el8_0, bind-chroot 9.11.4-19.P2.el8_0, bind-pkcs11 9.11.4-19.P2.el8_0, +6 more
fixed: vendor fix RHSA-2020:2404
Red Hat Enterprise Linux AppStream EUS (v. 8.1) bind 9.11.4-26.P2.el8_1.3, bind-sdb 9.11.4-26.P2.el8_1.3, bind-libs 9.11.4-26.P2.el8_1.3, bind-utils 9.11.4-26.P2.el8_1.3, bind-chroot 9.11.4-26.P2.el8_1.3, bind-pkcs11 9.11.4-26.P2.el8_1.3, +6 more
fixed: vendor fix RHSA-2020:2345
Red Hat Enterprise Linux BaseOS (v. 8) bind 9.11.13-5.el8_2, bind-export-libs 9.11.13-5.el8_2
fixed: vendor fix RHSA-2020:2338
Red Hat Enterprise Linux BaseOS E4S (v. 8.0) bind 9.11.4-19.P2.el8_0, bind-export-libs 9.11.4-19.P2.el8_0
fixed: vendor fix RHSA-2020:2404
Red Hat Enterprise Linux BaseOS EUS (v. 8.1) bind 9.11.4-26.P2.el8_1.3, bind-export-libs 9.11.4-26.P2.el8_1.3
fixed: vendor fix RHSA-2020:2345
Red Hat Enterprise Linux Client (v. 7) bind 9.11.4-16.P2.el7_8.6, bind-libs 9.11.4-16.P2.el7_8.6, bind-utils 9.11.4-16.P2.el7_8.6, bind-license 9.11.4-16.P2.el7_8.6, bind-libs-lite 9.11.4-16.P2.el7_8.6, bind-export-libs 9.11.4-16.P2.el7_8.6 Red Hat Enterprise Linux Client Optional (v. 7) bind 9.11.4-16.P2.el7_8.6, bind-sdb 9.11.4-16.P2.el7_8.6, bind-chroot 9.11.4-16.P2.el7_8.6, bind-pkcs11 9.11.4-16.P2.el7_8.6, bind-sdb-chroot 9.11.4-16.P2.el7_8.6, bind-pkcs11-libs 9.11.4-16.P2.el7_8.6, +1 more Red Hat Enterprise Linux ComputeNode (v. 7) bind 9.11.4-16.P2.el7_8.6, bind-libs 9.11.4-16.P2.el7_8.6, bind-utils 9.11.4-16.P2.el7_8.6, bind-license 9.11.4-16.P2.el7_8.6, bind-libs-lite 9.11.4-16.P2.el7_8.6, bind-export-libs 9.11.4-16.P2.el7_8.6
fixed: vendor fix RHSA-2020:2344

show 26 more

Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) bind 9.9.4-74.el7_6.4, bind-libs 9.9.4-74.el7_6.4, bind-utils 9.9.4-74.el7_6.4, bind-license 9.9.4-74.el7_6.4, bind-libs-lite 9.9.4-74.el7_6.4
fixed: vendor fix RHSA-2020:3475
Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) bind 9.11.4-9.P2.el7_7.1, bind-libs 9.11.4-9.P2.el7_7.1, bind-utils 9.11.4-9.P2.el7_7.1, bind-license 9.11.4-9.P2.el7_7.1, bind-libs-lite 9.11.4-9.P2.el7_7.1, bind-export-libs 9.11.4-9.P2.el7_7.1
fixed: vendor fix RHSA-2020:2893
Red Hat Enterprise Linux ComputeNode Optional (v. 7) bind 9.11.4-16.P2.el7_8.6, bind-sdb 9.11.4-16.P2.el7_8.6, bind-chroot 9.11.4-16.P2.el7_8.6, bind-pkcs11 9.11.4-16.P2.el7_8.6, bind-sdb-chroot 9.11.4-16.P2.el7_8.6, bind-pkcs11-libs 9.11.4-16.P2.el7_8.6, +1 more
fixed: vendor fix RHSA-2020:2344
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) bind 9.9.4-74.el7_6.4, bind-sdb 9.9.4-74.el7_6.4, bind-chroot 9.9.4-74.el7_6.4, bind-pkcs11 9.9.4-74.el7_6.4, bind-sdb-chroot 9.9.4-74.el7_6.4, bind-pkcs11-libs 9.9.4-74.el7_6.4, +1 more
fixed: vendor fix RHSA-2020:3475
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) bind 9.11.4-9.P2.el7_7.1, bind-sdb 9.11.4-9.P2.el7_7.1, bind-chroot 9.11.4-9.P2.el7_7.1, bind-pkcs11 9.11.4-9.P2.el7_7.1, bind-sdb-chroot 9.11.4-9.P2.el7_7.1, bind-pkcs11-libs 9.11.4-9.P2.el7_7.1, +1 more
fixed: vendor fix RHSA-2020:2893
Red Hat Enterprise Linux Desktop (v. 6) bind 9.8.2-0.68.rc1.el6_10.7, bind-libs 9.8.2-0.68.rc1.el6_10.7, bind-utils 9.8.2-0.68.rc1.el6_10.7 Red Hat Enterprise Linux Desktop Optional (v. 6) bind 9.8.2-0.68.rc1.el6_10.7, bind-sdb 9.8.2-0.68.rc1.el6_10.7, bind-chroot 9.8.2-0.68.rc1.el6_10.7
fixed: vendor fix RHSA-2020:2383
Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) bind 9.9.4-74.el7_6.4, bind-libs 9.9.4-74.el7_6.4, bind-utils 9.9.4-74.el7_6.4, bind-chroot 9.9.4-74.el7_6.4, bind-pkcs11 9.9.4-74.el7_6.4, bind-license 9.9.4-74.el7_6.4, +3 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) bind-sdb 9.9.4-74.el7_6.4, bind-pkcs11 9.9.4-74.el7_6.4, bind-sdb-chroot 9.9.4-74.el7_6.4, bind-pkcs11-libs 9.9.4-74.el7_6.4, bind-pkcs11-utils 9.9.4-74.el7_6.4
fixed: vendor fix RHSA-2020:3475
Red Hat Enterprise Linux HPC Node (v. 6) bind 9.8.2-0.68.rc1.el6_10.7, bind-libs 9.8.2-0.68.rc1.el6_10.7, bind-utils 9.8.2-0.68.rc1.el6_10.7 Red Hat Enterprise Linux HPC Node Optional (v. 6) bind 9.8.2-0.68.rc1.el6_10.7, bind-sdb 9.8.2-0.68.rc1.el6_10.7, bind-chroot 9.8.2-0.68.rc1.el6_10.7 Red Hat Enterprise Linux Server (v. 6) bind 9.8.2-0.68.rc1.el6_10.7, bind-libs 9.8.2-0.68.rc1.el6_10.7, bind-utils 9.8.2-0.68.rc1.el6_10.7, bind-chroot 9.8.2-0.68.rc1.el6_10.7
fixed: vendor fix RHSA-2020:2383
Red Hat Enterprise Linux Server (v. 7) bind 9.11.4-16.P2.el7_8.6, bind-libs 9.11.4-16.P2.el7_8.6, bind-utils 9.11.4-16.P2.el7_8.6, bind-chroot 9.11.4-16.P2.el7_8.6, bind-pkcs11 9.11.4-16.P2.el7_8.6, bind-license 9.11.4-16.P2.el7_8.6, +4 more
fixed: vendor fix RHSA-2020:2344
Red Hat Enterprise Linux Server AUS (v. 6.5) bind 9.8.2-0.23.rc1.el6_5.9, bind-libs 9.8.2-0.23.rc1.el6_5.9, bind-utils 9.8.2-0.23.rc1.el6_5.9, bind-chroot 9.8.2-0.23.rc1.el6_5.9
fixed: vendor fix RHSA-2020:3379
Red Hat Enterprise Linux Server AUS (v. 6.6) bind 9.8.2-0.30.rc1.el6_6.11, bind-libs 9.8.2-0.30.rc1.el6_6.11, bind-utils 9.8.2-0.30.rc1.el6_6.11, bind-chroot 9.8.2-0.30.rc1.el6_6.11
fixed: vendor fix RHSA-2020:3378
Red Hat Enterprise Linux Server AUS (v. 7.2) bind 9.9.4-29.el7_2.9, bind-libs 9.9.4-29.el7_2.9, bind-utils 9.9.4-29.el7_2.9, bind-chroot 9.9.4-29.el7_2.9, bind-pkcs11 9.9.4-29.el7_2.9, bind-license 9.9.4-29.el7_2.9, +3 more
fixed: vendor fix RHSA-2020:3471
Red Hat Enterprise Linux Server AUS (v. 7.3) bind 9.9.4-50.el7_3.4, bind-libs 9.9.4-50.el7_3.4, bind-utils 9.9.4-50.el7_3.4, bind-chroot 9.9.4-50.el7_3.4, bind-pkcs11 9.9.4-50.el7_3.4, bind-license 9.9.4-50.el7_3.4, +3 more
fixed: vendor fix RHSA-2020:3470
Red Hat Enterprise Linux Server AUS (v. 7.4) bind 9.9.4-51.el7_4.4, bind-libs 9.9.4-51.el7_4.4, bind-utils 9.9.4-51.el7_4.4, bind-chroot 9.9.4-51.el7_4.4, bind-pkcs11 9.9.4-51.el7_4.4, bind-license 9.9.4-51.el7_4.4, +3 more
fixed: vendor fix RHSA-2020:3433
Red Hat Enterprise Linux Server E4S (v. 7.3) bind 9.9.4-50.el7_3.4, bind-libs 9.9.4-50.el7_3.4, bind-utils 9.9.4-50.el7_3.4, bind-chroot 9.9.4-50.el7_3.4, bind-pkcs11 9.9.4-50.el7_3.4, bind-license 9.9.4-50.el7_3.4, +3 more
fixed: vendor fix RHSA-2020:3470
Red Hat Enterprise Linux Server E4S (v. 7.4) bind 9.9.4-51.el7_4.4, bind-libs 9.9.4-51.el7_4.4, bind-utils 9.9.4-51.el7_4.4, bind-chroot 9.9.4-51.el7_4.4, bind-pkcs11 9.9.4-51.el7_4.4, bind-license 9.9.4-51.el7_4.4, +3 more
fixed: vendor fix RHSA-2020:3433
Red Hat Enterprise Linux Server EUS (v. 7.6) bind 9.9.4-74.el7_6.4, bind-libs 9.9.4-74.el7_6.4, bind-utils 9.9.4-74.el7_6.4, bind-chroot 9.9.4-74.el7_6.4, bind-pkcs11 9.9.4-74.el7_6.4, bind-license 9.9.4-74.el7_6.4, +3 more
fixed: vendor fix RHSA-2020:3475
Red Hat Enterprise Linux Server EUS (v. 7.7) bind 9.11.4-9.P2.el7_7.1, bind-libs 9.11.4-9.P2.el7_7.1, bind-utils 9.11.4-9.P2.el7_7.1, bind-chroot 9.11.4-9.P2.el7_7.1, bind-pkcs11 9.11.4-9.P2.el7_7.1, bind-license 9.11.4-9.P2.el7_7.1, +4 more
fixed: vendor fix RHSA-2020:2893
Red Hat Enterprise Linux Server Optional (v. 6) bind-sdb 9.8.2-0.68.rc1.el6_10.7
fixed: vendor fix RHSA-2020:2383
Red Hat Enterprise Linux Server Optional (v. 7) bind-sdb 9.11.4-16.P2.el7_8.6, bind-sdb-chroot 9.11.4-16.P2.el7_8.6
fixed: vendor fix RHSA-2020:2344
Red Hat Enterprise Linux Server Optional AUS (v. 6.5) bind 9.8.2-0.23.rc1.el6_5.9, bind-sdb 9.8.2-0.23.rc1.el6_5.9
fixed: vendor fix RHSA-2020:3379
Red Hat Enterprise Linux Server Optional AUS (v. 6.6) bind-sdb 9.8.2-0.30.rc1.el6_6.11
fixed: vendor fix RHSA-2020:3378
Red Hat Enterprise Linux Server Optional AUS (v. 7.2) bind-sdb 9.9.4-29.el7_2.9, bind-sdb-chroot 9.9.4-29.el7_2.9
fixed: vendor fix RHSA-2020:3471
Red Hat Enterprise Linux Server Optional AUS (v. 7.3) bind-sdb 9.9.4-50.el7_3.4, bind-sdb-chroot 9.9.4-50.el7_3.4
fixed: vendor fix RHSA-2020:3470
Red Hat Enterprise Linux Server Optional AUS (v. 7.4) bind-sdb 9.9.4-51.el7_4.4, bind-sdb-chroot 9.9.4-51.el7_4.4
fixed: vendor fix RHSA-2020:3433
Red Hat Enterprise Linux Server Optional E4S (v. 7.3) bind-sdb 9.9.4-50.el7_3.4, bind-sdb-chroot 9.9.4-50.el7_3.4
fixed: vendor fix RHSA-2020:3470

11 more fixed in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

2020-05-19 First public exploit (Metasploit auxiliary/dos/dns/bind_tsig_badtime)
2020-05-19 Published

Exploit prediction

93.33% chance of exploitation in the next 30 days, higher than 99.8% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Metasploit auxiliary/dos/dns/bind_tsig_badtime BIND TSIG Badtime Query Denial of Service metasploit auxiliary, normal rank, 2020-05-19
EDB-48521 BIND - 'TSIG' Denial of Service dos, 2020-05-20

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

ISC BIND9

Classification

Weakness

CWE-617 Reachable Assertion

References

kb.isc.org /docs/cve-2020-8617
patch, vendor-advisory
openwall.com /lists/oss-security/2020/05/19/4
mailing-list, patch, third-party-advisory
debian.org /security/2020/dsa-4689
vendor-advisory, third-party-advisory
usn.ubuntu.com /4365-2/
vendor-advisory, third-party-advisory
usn.ubuntu.com /4365-1/
vendor-advisory, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/WOGCJS2XQ3SQNF4W6GLZ73LWZJ6ZZWZI/
vendor-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/JKJXVBOKZ36ER3EUCR7VRB7WGHIIMPNJ/
vendor-advisory
lists.opensuse.org /opensuse-security-announce/2020-10/msg00041.html
vendor-advisory, mailing-list, third-party-advisory
lists.opensuse.org /opensuse-security-announce/2020-10/msg00044.html
vendor-advisory, mailing-list, third-party-advisory
security.netapp.com /advisory/ntap-20200522-0002/
third-party-advisory
packetstormsecurity.com /files/157836/BIND-TSIG-Denial-Of-Service.html
third-party-advisory, vdb-entry
lists.debian.org /debian-lts-announce/2020/05/msg00031.html
mailing-list, third-party-advisory

Sources

CVE List CVE-2020-8617
NVD CVE-2020-8617

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary