I am re-posting my thread that is on S7 before any of you get the chance to.

To most of you, this is known as tehpoison's method to bring cmr's online. He was the first person to demonstrate the glitch, and a few days after he released his modified classes, I found out his method independently, and worked 50+ hours over the course of 2 months finding every possible thing related to this glitch, so in essence, we are both the founders and please give credit for where credit is due. I am not 100% sure that this is his method, but I am almost certain it is. This method is the most powerful exploit that has been done on a retail mw3 since the release of vault mods, which has since been patched. Many methods such as 18 man FFA, modified public classes, play any gametype online (now restricted to only default variants), modified private match classes, prestige token glitch, and 15 custom classes are all now possible with this method. I will explain in great detail each method using the system-link exploit, or SLE for short.


The System-Link Exploit (SLE):

Requirements:
two controllers

Tutorial:
1. Have controller one be your main controller. Make sure you have an xbox live gold account signed in on controller one, and have controller two be turned on, but do not have anyone signed in on controller two.
2. Go to the mp menu, and with the second controller, highlight system-link and press "A". Nothing should happen, but now your account is primed to use the SLE.
3. In any menu/interface of the multiplayer side of the game, sign in to an account with your second controller using the xbox button, and it will bring you to system-link signed in as your first account. So mainly for all purposes, the second account is irrelevant and your main account should be on the first controller.

Note: This only works on the mp side of the game. If you go to campaign or spec ops, SLE will become ineffective. This also does not work after you save information to the hdd or usb on the xbox. If this is the case, you need to redo the SLE from step one. Also, SLE does not work in-game.


18 Man FFA:

Requirements:
At least one friend

Tutorial:
1. Search for a game of FFA. You only need to be in the search for a few seconds. This is what decides the gametype of the 18 man lobby you want to host.
1. Prime SLE
2. Go in to a private match lobby, and then sign in using your second controller. This brings you to system-link, but if you back out of system-link, you will be in the private match and the timer should start to go down.
3. End the game that started, and you will now be placed in the exact same search lobby you were in step 1, except there will be slots for 18 people.

Note: You need to have the required minimal players before the match will start. If you only have yourself and friend to do it with, go back to step 1 and search for a 1v1 match.


Online CMR (currently only works with default gametypes):

Tutorial:
1. Go to a private match and go to the settings. Change all of the settings you want the pub match to run on. The only settings that will stick currently are the map and game type, which can be any of the game types that are available.
2. Prime SLE
3. Go back to the private match and sign in to your second controller. Back out and the timer will have started for the match.

Note: This has the same requirements as the FFA lobby.


Modded Custom Classes (Public):

Requirements:
Modified mp save - I will add downloads of my templates that I use. To make your own, you can modify the first 15 custom classes that appear in hex, and also make sure to modify the level and gun xp so you can use all guns and attachments.

Tutorial:
1. Put the modifed MP save in your storage device.
2. Go to split-screen, and when you are at the player selection screen, make sure to select your storage device that has the modified data.
3. Back out to the lobby and prime SLE.
4. Go back to system-link, start a game lobby with competition mode disabled, and go to custom classes. Pick the custom class you want to copy to your main account and click copy. Keep it in the copy selection screen.
5. Sign in to your second account.
6. You should now be in system link. With your first controller, press back once and you should be in the custom class interface. It won't be the modified class but don't worry. Select the desired slot you want the modified class in and press "A".

Note: You need to have the required unlocks to use in a pub match. This does not unlock anything for you except guns that have no requirements, like jug guns and marine camo. Since I and others made this publicly available, the effectiveness of the modifications are somewhat limited. Currently what works is:
modifying specialist KS and their respective KS requirment
non-care package turrets and assault drones
Silenced desert eagles, and other varients
Jug guns
Button/colors in class names
Marine and winter camo
Dual guns, such as two riot shields. Still needs overkill to work correctly.


Modded Custom Classes (Private):

Same as above, except in step 4, enable competition mode. The classes you have to modify in the file are the 5 classes after the 15 public match custom classes.

Note: These classes go under the same limitations as the public custom classes.


Prestige Token Glitch (Reborn):

Requirements:
Modified MP save, unless you have a legit prestige token from split-screen

Tutorial:
1. Put the modifed MP save in your storage device.
2. Go to split-screen, and when you are at the player selection screen, make sure to select your storage device that has the modified data.
3. Back out and prime the SLE.
4. Go to system-link and go to barracks, then go to prestige shop and select any that you desire.
5. Sign in to your second account
6. With your first account, press back and you can then accept the purchase without requiring the use of a token.

Note: This will give you negative prestige tokens. Currently they are not looking for them, but once this gets abused, it could be something they look for if they are going to ban accounts. Also, this process has to be repeated from step 3 for multiple transactions.

Tips: To buy all of the unlock-ables without re-doing the method, do the above steps 1-4 and when you are purchasing a prestige shop item, go to the unlocks and select something that you have already selected on your public account, then do steps 5-6 and then you will be in the unlock interface, and you can spend unlimited prestige tokens as long as you are in the unlock interface.

Also, 15 Custom Classes are back! Do the above 1-6 steps, but make sure to select add custom class slot for step 4. Note that the game can only use 15 slots, so if you start purchasing slots past 15, it will have no good effect.

This method is also how you can reset stats at ANY level.


Watch Theater Videos Anywhere:

Tutorial:
1. Prime the theater glitch. To do this go to your vault, and then join someone else's game while you are still viewing your vault.
2. Prime the SLE.
3. Go to split-screen. Go to options, game-type, and then go to your vault.
4. Press back once and now you should be able to select any video in your vault.
5. Select preferably a long clip and click play.
6. After it starts loading, sign in with your second account.
7. You will now be in a glitched split-screen lobby, back out to the multiplayer menu. What this does is it keeps loading the video in the background and once it is done loading, the video will start.

Note: There are several uses for this, for one using the 21st prestige glitch in any lobby. There also may be other uses for this that I have not found yet, like making the vault mods/21st prestige to stick.


Reset Guest in Lobby:

Requirements:
Main account with 20th prestige
One prestige token

Tutorial:
1. Prime the SLE
2. Go to an xbox live lobby, and click "A" on the second controller to initiate the sign-in. Sign in as a guest.
3. Navigate the system-link menu with your second controller and go to barracks. Then go to the prestige shop and it should be your guest in the shop. Now you can buy anything for your guest, even the reset option.

Note: Make sure it is your guest in the lobby! To the right of your screen, you can see if it is your main or guest. To undo the glitch, you can sign your guest off and sign it back on.



These are all of the current uses I know using the SLE. If I remember something that I forgot, I will post it when I get free time today, plus all of the videos that I have associated with this glitch and the downloads for the templates that I use for the modified classes. If you want to re-post this or make a video, please give credit for the work I have done. Plagiarism is the main reason why this is going to be my last public release. Enjoy this while it last guys, and I do feel bad for previously charging for this service, but the custom work required per account equaled the price offered. Didn't try to rip anyone off like the $90 challenge lobbies.