CVE:                 CVE-2020-8618
Document version:    2.0
Posting date:        17 June 2020
Program impacted:    BIND
Versions affected:   BIND 9.16.0 -> 9.16.3
Severity:            Medium




   An assertion check in BIND (that is meant to prevent going beyond
   the end of a buffer when processing incoming data) can be
   incorrectly triggered by a large response during zone transfer.


   An attacker who is permitted to send zone data to a server via
   zone transfer can exploit this to intentionally trigger the
   assertion failure with a specially constructed zone, denying
   service to clients.

CVSS Score:          4.3
CVSS Vector:         AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

For more information on the Common Vulnerability Scoring System and
to obtain your specific environmental score please visit:



Active exploits:

   We are not aware of any active exploits.


   Upgrade to the patched release most closely related to your
   current version of BIND:

   -  BIND 9.16.4

Document revision history:

   1.0 Early Notification, 10 June 2020
   1.1 Simplified "Exploitable" section, 17 June 2020
   2.0 Public disclosure, 17 June 2020

Related documents:

   See our BIND 9 Security Vulnerability Matrix for a complete
   listing of security vulnerabilities and versions affected.

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