Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
0

Some versions of BIND can improperly permit recursive query service to unauthorized clients

Disclosure Date: January 16, 2019
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

Change #4777 (introduced in October 2017) introduced an unforeseen issue in releases which were issued after that date, affecting which clients are permitted to make recursive queries to a BIND nameserver. The intended (and documented) behavior is that if an operator has not specified a value for the “allow-recursion” setting, it SHOULD default to one of the following: none, if “recursion no;” is set in named.conf; a value inherited from the “allow-query-cache” or “allow-query” settings IF “recursion yes;” (the default for that setting) AND match lists are explicitly set for “allow-query-cache” or “allow-query” (see the BIND9 Administrative Reference Manual section 6.2 for more details); or the intended default of “allow-recursion {localhost; localnets;};” if “recursion yes;” is in effect and no values are explicitly set for “allow-query-cache” or “allow-query”. However, because of the regression introduced by change #4777, it is possible when “recursion yes;” is in effect and no match list values are provided for “allow-query-cache” or “allow-query” for the setting of “allow-recursion” to inherit a setting of all hosts from the “allow-query” setting default, improperly permitting recursion to all clients. Affects BIND 9.9.12, 9.10.7, 9.11.3, 9.12.0->9.12.1-P2, the development release 9.13.0, and also releases 9.9.12-S1, 9.10.7-S1, 9.11.3-S1, and 9.11.3-S2 from BIND 9 Supported Preview Edition.

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CVSS V3 Severity and Metrics
Base Score:
7.5 High
Impact Score:
3.6
Exploitability Score:
3.9
Vector:
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
None
Availability (A):
None

General Information

Vendors

  • canonical,
  • isc

Products

  • bind 9.10.7,
  • bind 9.11.3,
  • bind 9.12.0,
  • bind 9.12.1,
  • bind 9.13.0,
  • bind 9.9.12,
  • ubuntu linux 18.04

Additional Info

Technical Analysis