From 7983015dfa58be21526a01300b9e13a84278266a Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Mon, 4 Jun 2018 21:55:41 -0700
Subject: [PATCH] allow-recursion could incorrectly inherit from the default
allow-query
---
bin/named/server.c | 50 ++++++++++++++++++++++++++++++++++++--------------
doc/arm/notes.xml | 41 +++++------------------------------------
2 files changed, 41 insertions(+), 50 deletions(-)
diff --git a/bin/named/server.c b/bin/named/server.c
index 64a5180..41a1826 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -3376,10 +3376,6 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist,
dns_acache_setcachesize(view->acache, max_acache_size);
}
- CHECK(configure_view_acl(vconfig, config, ns_g_config,
- "allow-query", NULL, actx,
- ns_g_mctx, &view->queryacl));
-
/*
* Make the list of response policy zone names for a view that
* is used for real lookups and so cares about hints.
@@ -4258,9 +4254,6 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist,
INSIST(result == ISC_R_SUCCESS);
view->trust_anchor_telemetry = cfg_obj_asboolean(obj);
- CHECK(configure_view_acl(vconfig, config, ns_g_config,
- "allow-query-cache-on", NULL, actx,
- ns_g_mctx, &view->cacheonacl));
/*
* Set sources where additional data and CNAME/DNAME
* targets for authoritative answers may be found.
@@ -4287,22 +4280,40 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist,
view->additionalfromcache = ISC_TRUE;
}
+ CHECK(configure_view_acl(vconfig, config, ns_g_config,
+ "allow-query-cache-on", NULL, actx,
+ ns_g_mctx, &view->cacheonacl));
+
/*
- * Set "allow-query-cache", "allow-recursion", and
- * "allow-recursion-on" acls if configured in named.conf.
- * (Ignore the global defaults for now, because these ACLs
- * can inherit from each other when only some of them set at
- * the options/view level.)
+ * Set the "allow-query", "allow-query-cache", "allow-recursion",
+ * and "allow-recursion-on" ACLs if configured in named.conf, but
+ * NOT from the global defaults. This is done by leaving the third
+ * argument to configure_view_acl() NULL.
+ *
+ * We ignore the global defaults here because these ACLs
+ * can inherit from each other. If any are still unset after
+ * applying the inheritance rules, we'll look up the defaults at
+ * that time.
*/
- CHECK(configure_view_acl(vconfig, config, NULL, "allow-query-cache",
- NULL, actx, ns_g_mctx, &view->cacheacl));
+
+ /* named.conf only */
+ CHECK(configure_view_acl(vconfig, config, NULL,
+ "allow-query", NULL, actx,
+ ns_g_mctx, &view->queryacl));
+
+ /* named.conf only */
+ CHECK(configure_view_acl(vconfig, config, NULL,
+ "allow-query-cache", NULL, actx,
+ ns_g_mctx, &view->cacheacl));
if (strcmp(view->name, "_bind") != 0 &&
view->rdclass != dns_rdataclass_chaos)
{
+ /* named.conf only */
CHECK(configure_view_acl(vconfig, config, NULL,
"allow-recursion", NULL, actx,
ns_g_mctx, &view->recursionacl));
+ /* named.conf only */
CHECK(configure_view_acl(vconfig, config, NULL,
"allow-recursion-on", NULL, actx,
ns_g_mctx, &view->recursiononacl));
@@ -4340,18 +4351,21 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist,
* the global config.
*/
if (view->recursionacl == NULL) {
+ /* global default only */
CHECK(configure_view_acl(NULL, NULL, ns_g_config,
"allow-recursion", NULL,
actx, ns_g_mctx,
&view->recursionacl));
}
if (view->recursiononacl == NULL) {
+ /* global default only */
CHECK(configure_view_acl(NULL, NULL, ns_g_config,
"allow-recursion-on", NULL,
actx, ns_g_mctx,
&view->recursiononacl));
}
if (view->cacheacl == NULL) {
+ /* global default only */
CHECK(configure_view_acl(NULL, NULL, ns_g_config,
"allow-query-cache", NULL,
actx, ns_g_mctx,
@@ -4365,6 +4379,14 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist,
CHECK(dns_acl_none(mctx, &view->cacheacl));
}
+ if (view->queryacl == NULL) {
+ /* global default only */
+ CHECK(configure_view_acl(NULL, NULL, ns_g_config,
+ "allow-query", NULL,
+ actx, ns_g_mctx,
+ &view->queryacl));
+ }
+
/*
* Ignore case when compressing responses to the specified
* clients. This causes case not always to be preserved,
diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml
index ea9b61f..9a1832d 100644
--- a/doc/arm/notes.xml
+++ b/doc/arm/notes.xml
@@ -103,42 +103,11 @@
<itemizedlist>
<listitem>
<para>
- An error in TSIG handling could permit unauthorized zone
- transfers or zone updates. These flaws are disclosed in
- CVE-2017-3142 and CVE-2017-3143. [RT #45383]
- </para>
- </listitem>
- <listitem>
- <para>
- The BIND installer on Windows used an unquoted service path,
- which can enable privilege escalation. This flaw is disclosed
- in CVE-2017-3141. [RT #45229]
- </para>
- </listitem>
- <listitem>
- <para>
- With certain RPZ configurations, a response with TTL 0
- could cause <command>named</command> to go into an infinite
- query loop. This flaw is disclosed in CVE-2017-3140.
- [RT #45181]
- </para>
- </listitem>
- <listitem>
- <para>
- Addresses could be referenced after being freed during resolver
- processing, causing an assertion failure. The chances of this
- happening were remote, but the introduction of a delay in
- resolution increased them. This bug is disclosed in
- CVE-2017-3145. [RT #46839]
- </para>
- </listitem>
- <listitem>
- <para>
- update-policy rules that otherwise ignore the name field now
- require that it be set to "." to ensure that any type list
- present is properly interpreted. If the name field was omitted
- from the rule declaration and a type list was present it wouldn't
- be interpreted as expected.
+ When recursion is enabled but the <command>allow-recursion</command>
+ and <command>allow-query-cache</command> ACLs are not specified, they
+ should be limited to local networks, but they were inadvertently set
+ to match the default <command>allow-query</command>, thus allowing
+ remote queries. This flaw is disclosed in CVE-2018-5738. [GL #309]
</para>
</listitem>
</itemizedlist>
--
2.14.4