Id:
CVE-2018-5738
Comment
:
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.
CVSSv2 Score:
5
Access vector:
|
NETWORK
|
Access complexity:
|
LOW
|
Authentication:
|
NONE
|
Confidentiality impact:
|
PARTIAL
|
Integrity impact:
|
NONE
|
Availability impact:
|
NONE
|
CVSSv2 Vector:
AV:N/AC:L/Au:N/C:P/I:N/A:N
CVSSv3 Score:
7.5
Attack vector:
|
NETWORK
|
Attack complexity:
|
LOW
|
Privileges required:
|
NONE
|
User interaction:
|
NONE
|
Scope:
|
UNCHANGED
|
Confidentiality impact:
|
HIGH
|
Integrity impact:
|
NONE
|
Availability impact:
|
NONE
|
CVSSv3 Vector:
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References: