CVE-2019-6469: BIND Supported Preview Edition can exit with an assertion failure if ECS is in use
Document version: 2.0
Posting date: 29 May 2019
Program impacted: BIND
Versions affected: BIND Supported Preview Edition version 9.10.5-S1 -> 9.11.6-S1. ONLY BIND Supported Preview Edition releases are affected.
An error in the EDNS Client Subnet (ECS) feature for recursive resolvers can cause BIND to exit with an assertion failure when processing a response that has malformed RRSIGs.
An attacker who is able to cause a server to perform a query whose answer will be accompanied by malformed RRSIGs can deliberately cause a server to exit if it is using the recursive ECS feature.
CVSS Score: 5.9
CVSS Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Only servers which have enabled the EDNS Client Subnet (ECS) feature can be affected by this defect; it can be prevented by disabling ECS options in the server's configuration.
Upgrade to the patched release most closely related to your current version of BIND:
BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers.
- BIND 9.11.7-S1
Acknowledgements: ISC would like to thank Quad9 for reporting this issue.
Document revision history:
1.0 Early Notification, 15 May 2019
2.0 Public Disclosure, 29 May 2019
See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected.
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ISC patches only currently supported versions. When possible we indicate EOL versions affected. (For current information on which versions are actively supported, please see https://www.isc.org/downloads/.)
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