|
 |
cab1c5 |
From e111def44a7df4624a4aa3f85fe98054bffb6b4f Mon Sep 17 00:00:00 2001
|
|
|
cab1c5 |
From: Trent Lloyd <trent@lloyd.id.au>
|
|
|
cab1c5 |
Date: Sat, 22 Dec 2018 09:06:07 +0800
|
|
|
cab1c5 |
Subject: [PATCH] Drop legacy unicast queries from address not on local link
|
|
|
cab1c5 |
|
|
|
cab1c5 |
When handling legacy unicast queries, ensure that the source IP is
|
|
|
cab1c5 |
inside a subnet on the local link, otherwise drop the packet.
|
|
|
cab1c5 |
|
|
|
cab1c5 |
Fixes #145
|
|
|
cab1c5 |
Fixes #203
|
|
|
cab1c5 |
CVE-2017-6519
|
|
|
cab1c5 |
CVE-2018-100084
|
|
|
cab1c5 |
---
|
|
|
cab1c5 |
avahi-core/server.c | 8 ++++++++
|
|
|
cab1c5 |
1 file changed, 8 insertions(+)
|
|
|
cab1c5 |
|
|
|
cab1c5 |
diff --git a/avahi-core/server.c b/avahi-core/server.c
|
|
|
cab1c5 |
index a2cb19a8..a2580e38 100644
|
|
|
cab1c5 |
--- a/avahi-core/server.c
|
|
|
cab1c5 |
+++ b/avahi-core/server.c
|
|
|
cab1c5 |
@@ -930,6 +930,7 @@ static void dispatch_packet(AvahiServer *s, AvahiDnsPacket *p, const AvahiAddres
|
|
|
cab1c5 |
|
|
|
cab1c5 |
if (avahi_dns_packet_is_query(p)) {
|
|
|
cab1c5 |
int legacy_unicast = 0;
|
|
|
cab1c5 |
+ char t[AVAHI_ADDRESS_STR_MAX];
|
|
|
cab1c5 |
|
|
|
cab1c5 |
/* For queries EDNS0 might allow ARCOUNT != 0. We ignore the
|
|
|
cab1c5 |
* AR section completely here, so far. Until the day we add
|
|
|
cab1c5 |
@@ -947,6 +948,13 @@ static void dispatch_packet(AvahiServer *s, AvahiDnsPacket *p, const AvahiAddres
|
|
|
cab1c5 |
legacy_unicast = 1;
|
|
|
cab1c5 |
}
|
|
|
cab1c5 |
|
|
|
cab1c5 |
+ if (!is_mdns_mcast_address(dst_address) &&
|
|
|
cab1c5 |
+ !avahi_interface_address_on_link(i, src_address)) {
|
|
|
cab1c5 |
+
|
|
|
cab1c5 |
+ avahi_log_debug("Received non-local unicast query from host %s on interface '%s.%i'.", avahi_address_snprint(t, sizeof(t), src_address), i->hardware->name, i->protocol);
|
|
|
cab1c5 |
+ return;
|
|
|
cab1c5 |
+ }
|
|
|
cab1c5 |
+
|
|
|
cab1c5 |
if (legacy_unicast)
|
|
|
cab1c5 |
reflect_legacy_unicast_query_packet(s, p, i, src_address, port);
|
|
|
cab1c5 |
|