CVE-2020-8617

Summary

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.

Impact & exploitability

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

Affected products we track (2)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: http://www.openwall.com/lists/oss-security/2020/05/19/4 ↗

Additional information

• NVD record
• http://www.openwall.com/lists/oss-security/2020/05/19/4Patch
• https://kb.isc.org/docs/cve-2020-8617Patch
• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.htmlAdvisory
• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.htmlAdvisory
• http://packetstormsecurity.com/files/157836/BIND-TSIG-Denial-Of-Service.htmlAdvisory
• https://lists.debian.org/debian-lts-announce/2020/05/msg00031.htmlAdvisory
• 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/