CVE-2020-8617
MediumPublic exploitUsing 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.
Published May 19, 2020 · Updated Aug 7, 2026 · Also known as ALPINE-CVE-2020-8617, DEBIAN-CVE-2020-8617, UBUNTU-CVE-2020-8617
Key Facts
Patch immediately- CVE-2020-8617 is a medium-severity vulnerability (CVSS 5.9 v3.1) affecting Bind (Isc), Ubuntu Linux (Canonical), Debian Linux and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 93% probability of exploitation in the next 30 days.
- Fixed versions are available, including Bind 32:9.11.13-5.el8_2, Bind 32:9.11.4-16.P2.el7_8.6, Bind 32:9.11.4-9.P2.amzn2.0.3.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
93%
Higher than 99.8% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2020-8617 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Affected Products
448 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| BindIsc | 9.10.5-s1, 9.10.7-s1, 9.11.3-s1, 9.11.5-s3, 9.11.5-s5, 9.11.6-s1, 9.11.7-s1, 9.11.8-s1 | 9.11.18 |
| Ubuntu LinuxCanonical | 12.04, 14.04, 16.04, 18.04, 19.10, 20.04 | n/a |
| Debian LinuxDebian | 10.0, 8.0, 9.0 | n/a |
| FedoraFedoraproject | 31, 32 | n/a |
| LeapOpensuse | 15.1, 15.2 | n/a |
Patched Releases
Bind
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3, 32:9.11.4-9.P2.el7_7.1, 32:9.8.2-0.23.rc1.el6_5.9, 32:9.8.2-0.68.rc1.64.amzn1, 32:9.8.2-0.68.rc1.el6_10.7, 9.11.2-3.17.1, 9.14.12-r0, 9.16.20-1.4, 9.16.3-1, 9.16.6-12.32.1, 9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1, 9.9.6P1-0.51.20.1, 9.9.9P1-63.17.1, <=9.11.18
bind-chroot
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3, 32:9.8.2-0.68.rc1.64.amzn1, 32:9.8.2-0.68.rc1.el6_10.7
bind-chrootenv
9.11.2-3.17.1, 9.16.6-12.32.1, 9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1, 9.9.6P1-0.51.20.1, 9.9.9P1-63.17.1
bind-devel
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3, 32:9.8.2-0.68.rc1.64.amzn1, 32:9.8.2-0.68.rc1.el6_10.7, 9.11.2-3.17.1, 9.16.6-12.32.1, 9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1, 9.9.6P1-0.51.20.1
bind-devel-32bit
9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1
bind-doc
9.11.2-3.17.1, 9.16.20-1.4, 9.16.6-12.32.1, 9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1, 9.9.6P1-0.51.20.1, 9.9.9P1-63.17.1
bind-export-devel
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-export-libs
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-libs
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3, 32:9.8.2-0.68.rc1.64.amzn1, 32:9.8.2-0.68.rc1.el6_10.7, 9.9.6P1-0.51.20.1, 9.9.9P1-63.17.1
bind-libs-32bit
9.9.6P1-0.51.20.1, 9.9.9P1-63.17.1
bind-libs-lite
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-license
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-lite-devel
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-pkcs11
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-pkcs11-devel
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-pkcs11-libs
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-pkcs11-utils
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-sdb
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3, 32:9.8.2-0.68.rc1.64.amzn1, 32:9.8.2-0.68.rc1.el6_10.7
bind-sdb-chroot
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3
bind-utils
32:9.11.13-5.el8_2, 32:9.11.4-16.P2.el7_8.6, 32:9.11.4-9.P2.amzn2.0.3, 32:9.8.2-0.68.rc1.64.amzn1, 32:9.8.2-0.68.rc1.el6_10.7, 9.11.2-3.17.1, 9.16.20-1.4, 9.16.6-12.32.1, 9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1, 9.9.6P1-0.51.20.1, 9.9.9P1-63.17.1
BIND9
1:9.10.3.dfsg.P4-12.3+deb9u6, 1:9.10.3.dfsg.P4-8ubuntu1.16, 1:9.11.3+dfsg-1ubuntu1.12, 1:9.11.5.P4+dfsg-5.1+deb10u1, 1:9.16.1-0ubuntu2.1, 1:9.16.3-1, 1:9.9.5.dfsg-3ubuntu0.19+esm2, 1:9.9.5.dfsg-9+deb8u19
bindutils
9.16.3-1.ph1, 9.16.3-1.ph2, 9.16.3-1.ph3, NA
libbind9-160
9.11.2-3.17.1
libbind9-1600
9.16.6-12.32.1, 9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1
libbind9-1600-32bit
9.16.6-lp151.11.9.1, 9.16.6-lp152.14.3.1
Timeline
Publicly disclosed
May 19, 2020
Last updated
Aug 7, 2026
Weakness Type
- CWE-617 Reachable Assertion
References
- advisoryopenSUSE-SU-2020:1699
- advisoryopenSUSE-SU-2020:1701
- advisoryhttp://packetstormsecurity.com/files/157836/BIND-TSIG-Denial-Of-Service.html
- advisoryRHSA-2020:2338
- advisoryRHSA-2020:2344
FAQ
Common Questions.
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.
Affected: Bind (Isc) versions 9.10.5-s1, 9.10.7-s1, 9.11.3-s1, 9.11.5-s3, 9.11.5-s5, 9.11.6-s1, 9.11.7-s1, 9.11.8-s1; Ubuntu Linux (Canonical) versions 12.04, 14.04, 16.04, 18.04, 19.10, 20.04; Debian Linux versions 10.0, 8.0, 9.0, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Bind 32:9.11.13-5.el8_2, Bind 32:9.11.4-16.P2.el7_8.6, Bind 32:9.11.4-9.P2.amzn2.0.3.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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