CVE-2020-8617 Information

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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

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@lists.fedoraproject.org/message/JKJXVBOKZ36ER3EUCR7VRB7WGHIIMPNJ/ https://lists.fedoraproject.org/archives/list/package-announce@lists.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

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.5