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.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Bind | Isc | 9.9.12 (including) | 9.9.12 (including) |
| Bind | Isc | 9.9.12-s1 (including) | 9.9.12-s1 (including) |
| Bind | Isc | 9.10.7 (including) | 9.10.7 (including) |
| Bind | Isc | 9.10.7-s1 (including) | 9.10.7-s1 (including) |
| Bind | Isc | 9.11.3 (including) | 9.11.3 (including) |
| Bind | Isc | 9.11.3-s1 (including) | 9.11.3-s1 (including) |
| Bind | Isc | 9.11.3-s2 (including) | 9.11.3-s2 (including) |
| Bind | Isc | 9.12.0 (including) | 9.12.0 (including) |
| Bind | Isc | 9.12.0-a1 (including) | 9.12.0-a1 (including) |
| Bind | Isc | 9.12.0-b1 (including) | 9.12.0-b1 (including) |
| Bind | Isc | 9.12.0-b2 (including) | 9.12.0-b2 (including) |
| Bind | Isc | 9.12.0-rc1 (including) | 9.12.0-rc1 (including) |
| Bind | Isc | 9.12.0-rc3 (including) | 9.12.0-rc3 (including) |
| Bind | Isc | 9.12.1 (including) | 9.12.1 (including) |
| Bind | Isc | 9.12.1-p1 (including) | 9.12.1-p1 (including) |
| Bind | Isc | 9.12.1-p2 (including) | 9.12.1-p2 (including) |
| Bind | Isc | 9.13.0 (including) | 9.13.0 (including) |
| Bind9 | Ubuntu | bionic | * |
| Bind9 | Ubuntu | devel | * |
There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:
Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:
Information exposures can occur in different ways:
It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.