By design, BIND is intended to limit the number of TCP clients that can be connected at any given time. The number of allowed connections is a tunable parameter which, if unset, defaults to a conservative value for most servers. Unfortunately, the code which was intended to limit the number of simultaneous connections contained an error which could be exploited to grow the number of simultaneous connections beyond this limit. Versions affected: BIND 9.9.0 -> 9.10.8-P1, 9.11.0 -> 9.11.6, 9.12.0 -> 9.12.4, 9.14.0. BIND 9 Supported Preview Edition versions 9.9.3-S1 -> 9.11.5-S3, and 9.11.5-S5. Versions 9.13.0 -> 9.13.7 of the 9.13 development branch are also affected. Versions prior to BIND 9.9.0 have not been evaluated for vulnerability to CVE-2018-5743.
CVSS Score
7.5
EPSS Score
0.015
Published
2019-10-09
A failure to free memory can occur when processing messages having a specific combination of EDNS options. Versions affected are: BIND 9.10.7 -> 9.10.8-P1, 9.11.3 -> 9.11.5-P1, 9.12.0 -> 9.12.3-P1, and versions 9.10.7-S1 -> 9.11.5-S3 of BIND 9 Supported Preview Edition. Versions 9.13.0 -> 9.13.6 of the 9.13 development branch are also affected.
CVSS Score
7.5
EPSS Score
0.045
Published
2019-10-09
"deny-answer-aliases" is a little-used feature intended to help recursive server operators protect end users against DNS rebinding attacks, a potential method of circumventing the security model used by client browsers. However, a defect in this feature makes it easy, when the feature is in use, to experience an assertion failure in name.c. Affects BIND 9.7.0->9.8.8, 9.9.0->9.9.13, 9.10.0->9.10.8, 9.11.0->9.11.4, 9.12.0->9.12.2, 9.13.0->9.13.2.
CVSS Score
7.5
EPSS Score
0.695
Published
2019-01-16
To provide fine-grained controls over the ability to use Dynamic DNS (DDNS) to update records in a zone, BIND 9 provides a feature called update-policy. Various rules can be configured to limit the types of updates that can be performed by a client, depending on the key used when sending the update request. Unfortunately, some rule types were not initially documented, and when documentation for them was added to the Administrator Reference Manual (ARM) in change #3112, the language that was added to the ARM at that time incorrectly described the behavior of two rule types, krb5-subdomain and ms-subdomain. This incorrect documentation could mislead operators into believing that policies they had configured were more restrictive than they actually were. This affects BIND versions prior to BIND 9.11.5 and BIND 9.12.3.
CVSS Score
6.5
EPSS Score
0.005
Published
2019-01-16
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.
CVSS Score
5.3
EPSS Score
0.018
Published
2019-01-16
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