Dnsruby provides advanced options like DNSSEC in its data format
and is a current and well supported library.
The infrastructure services - resolver, server, etc, were designed
for a standalone configuration, and carry entirely too much weight
and redundancy to implement for this context. Instead of porting
over their native resolver, update the Net::DNS subclassed Rex
Resolver to use Dnsruby data formats and method calls.
Update the Msf namespace infrastructure mixins and native server
module with new method calls and workarounds for some instance
variables having only readers without writers. Implement the Rex
ServerManager to start and stop the DNS service adding relevant
alias methods to the Rex::Proto::DNS::Server class.
Rex services are designed to be modular and lightweight, as well
as implement the sockets, threads, and other low-level interfaces.
Dnsruby's operations classes implement their own threading and
socket semantics, and do not fit with the modular mixin workflow
used throughout Framework. So while the updated resolver can be
seen as adding rubber to the tire fire, converting to dnsruby's
native classes for resolvers, servers, and caches, would be more
like adding oxy acetylene and heavy metals.
Testing:
Internal tests for resolution of different record types locally
and over pivot sessions.
DNS spoofing module should be feature complete, with forwarding of
requests which do not have cached answers (can be disabled same as
the native server module), empty replies to reduce client wait on
outstanding DNS requests, and post-send output in verbose mode
to reduce garbage and execution time in the critical/racy path.
This module is best used in conditions where MITM is achieved by
way of MAC spoofing, route interception, or compromise of an inline
host on the datapath. The attacker should avoid forwarding
original requests to the intended destination, or if this is not
possible, prevent replies from traversing the MITM space in order
to avoid race conditions between the spoofer and victim.
Example iptables configuration on MITM host:
iptables -t nat -A POSTROUTING -o eth0 -p udp ! --dport 53 -j ...
Testing:
Internal testing in Virtualbox local network, atop 802.11, and
mostly in Neutron (with port security disabled on the VIFs) atop
OpenStack Liberty ML2+OVS.
Allow retrieval of '*' from stored static entries for spoofing
all domains to any IP using wildcard names. Replace the wildcard
response with the name submitted to the search in the response.
Fix improper checks in DNS::Packet for Resolv objects from decode
to encode.
Misc cleanup for records not responding to :address, convenience
methods, and packet structure.
Wei Chen
h00die
Brent Cook
Erin Bleiweiss
William Vu
asoto-r7
Spencer McIntyre
RageLtMan
Pearce Barry
Craig Smith
Brent Cook
g0tmi1k