In #4475, I incorrectly interpreted the role of the 'incomplete' array
in monitor_socket, and that change should be reverted.
What appears to happen is, we play a kind of 3-card monty with the list
of received packets that are waiting for a handler to use them.
monitor_socket continually loops between putting the packets on @pqueue,
then into backlog[] to sort them, then into incomplete[] to list all of
the packets that did not have handlers, finally back into @pqueue again.
If packets don't continually get shuffled back into incomplete, they are
not copied back into @pqueue to get rescanned again.
The only reason anything should really get into incomplete[] is if we
receive a packet, but there is nothing to handle it. This scenario
sounds like a bug, but it is exactly what happens with the Tcp Client
channel - one can open a new channel, and receive a response packet back
from the channel before the subsequent read_once code runs to register a
handler to actually process it. This would be akin to your OS
speculatively accepting data on a TCP socket with no listener, then when
you open the socket for the first time, its already there.
While it would be nice if the handlers were setup before the data was
sent back, rather than relying on a handler being registered some time
between connect and PacketTimeout, this needs to get in now to stop the
bleeding. The original meterpreter crash issue from #4475 appears to be
gone as well.
Don't validate checksums by default until they are better understood
Handle the unknowns a bit better
Make checksum failures more obvious why it failed
When using the Meterpreter Binaries gem to locate the path to the
meterpreter DLLs, it's not necessary to use File.expand_path on
the result because the gem's code does this already.
This commit simple removes those unnecessary calls.
Since Ruby 2.1, the respond_to? method is more strict because it does
not check protected methods. So when you use send(), clearly you're
ignoring this type of access control. The patch is meant to preserve
this behavior to avoid potential breakage.
Resolve#4507
When a meterpreter binary cannot be found, give the user some hint about what
went wrong.
```
msf > use exploit/multi/handler
msf exploit(handler) > set payload windows/meterpreter/reverse_tcp
payload => windows/meterpreter/reverse_tcp
msf exploit(handler) > set lhost 192.168.43.1
lhost => 192.168.43.1
msf exploit(handler) > exploit
[*] Started reverse handler on 192.168.43.1:4444
[*] Starting the payload handler...
[*] Sending stage (770048 bytes) to 192.168.43.252
[*] Meterpreter session 1 opened (192.168.43.1:4444 -> 192.168.43.252:49297) at 2014-12-29 12:32:37 -0600
meterpreter > use mack
Loading extension mack...
[-] Failed to load extension: No module of the name ext_server_mack.x86.dll found
```
This is also useful for not scaring away would-be developers who replaced only
half (the wrong half) of their DLLs from a fresh meterpreter build and
everything exploded. Not that thats ever happened to me :)
The current logic times out every packet almost immediately, making it possible
for almost any non-trivial meterpreter session to receive duplicate packets.
This causes problems especially with any interactions that involve passing
resource handles or pointers back and forth between MSF and meterpreter, since
meterpreter can be told to operate on freed pointers, double-closes, etc.
This probably fixes tons of heisenbugs, including #3798.
To reproduce this, I enabled all debug messages in meterpreter to slow it
down, then ran this RC script with a reverse TCP meterpreter, after linking in
the test modules:
(cd modules/post
ln -s ../../test/modules/post/test)
die.rc:
use exploit/multi/handler
set payload windows/meterpreter/reverse_tcp
set lhost 192.168.43.1
exploit -j
sleep 5
use post/test/services
set SESSION 1
run
Brent Cook
William Vu
nstarke
jvazquez-r7
sgabe
Jon Hart
Meatballs
OJ
sinn3r
Christian Mehlmauer
Tod Beardsley