CVE-2020-8617 EXPLOIT
7.5
HIGH · CVSS 3.1 · EPSS 93.4% (pctl 100)
Patch early
A public exploit exists.
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.
Scoring
| CVSS | 7.5 (HIGH, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| EPSS | 93.42% — more likely to be exploited than 100% of all CVEs |
| Weakness | CWE-617 |
| On CISA KEV | no |
| Public exploit | yes |
| Published | 2020-05-19 |
| Last modified | 2026-06-17 |
Affected (5)
| Vendor | Product |
|---|---|
| canonical | ubuntu linux |
| debian | debian linux |
| fedoraproject | fedora |
| isc | bind |
| opensuse | leap |
Public exploits
| Source | Title | Date |
|---|---|---|
| exploit-db | BIND - 'TSIG' Denial of Service | 2020-05-20 |
References
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html
- http://packetstormsecurity.com/files/157836/BIND-TSIG-Denial-Of-Service.html
- http://www.openwall.com/lists/oss-security/2020/05/19/4
- https://kb.isc.org/docs/cve-2020-8617
- https://lists.debian.org/debian-lts-announce/2020/05/msg00031.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKJXVBOKZ36ER3EUCR7VRB7WGHIIMPNJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WOGCJS2XQ3SQNF4W6GLZ73LWZJ6ZZWZI/
- https://security.netapp.com/advisory/ntap-20200522-0002/
- https://usn.ubuntu.com/4365-1/
- https://usn.ubuntu.com/4365-2/
- https://www.debian.org/security/2020/dsa-4689
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html
- http://packetstormsecurity.com/files/157836/BIND-TSIG-Denial-Of-Service.html
- http://www.openwall.com/lists/oss-security/2020/05/19/4
- https://kb.isc.org/docs/cve-2020-8617
- https://lists.debian.org/debian-lts-announce/2020/05/msg00031.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKJXVBOKZ36ER3EUCR7VRB7WGHIIMPNJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WOGCJS2XQ3SQNF4W6GLZ73LWZJ6ZZWZI/
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