@Eminem, @AdamGuerbuez has just sent you a tip for 2500 Dollars! Pick it up here ➔ https://t.co/duQGGywfBC
— ChangeTip (@ChangeTip) November 23, 2015
@FlavorFlav, congratulations! @AdamGuerbuez just sent you a tip for 1500 Dollars! Collect it here ➔ https://t.co/AwaNeCbDxQ
— ChangeTip (@ChangeTip) November 23, 2015
@MagicalTux, I just put 500 Dollars into your pocket on behalf of @AdamGuerbuez. About ChangeTip➔https://t.co/lNyIDookZ0
— ChangeTip (@ChangeTip) November 23, 2015
@JustinTrudeau, congratulations! @AdamGuerbuez just sent you a tip for 500 Dollars! Collect it here ➔ https://t.co/h1C3QuUAo1
— ChangeTip (@ChangeTip) November 23, 2015
@realDonaldTrump, congratulations! @AdamGuerbuez just sent you a tip for 800 Dollars! Collect it here ➔ https://t.co/UxqxA01h6a
— ChangeTip (@ChangeTip) November 23, 2015
@AdamGuerbuez @OKCoinBTC @ChangeTip You've tipped a couple thousand dollars just this morning, crazy shit #BTCPROMO
— lump bets (@lumpbets) November 23, 2015
@AdamGuerbuez @CoinTelegraph @ChangeTip balling!!
— CryptoChrisG (@CryptoChrisG) November 23, 2015
@AdamGuerbuez Adam, bro. What's up with tipping wealthy celebrities? Your young trap nigga over here could really use a little love! □□
— Blockchain Gucci Mān (@CryptoTrap) November 23, 2015
@AdamGuerbuez @FlavorFlav @ChangeTip Oh men I'm a poor trader in a poor rich country share some love
— BitcoinLoopVen (@Bitcoinloopven) November 23, 2015
.@AdamGuerbuez That tip for @MagicalTux is pure evil dude.
— Or Weinberger (@orweinberger) November 25, 2015
However it turns out that despite fooling most people, the tips were not exactly what they appeared to be. You've probably figured out now that something's not quite right, and that a little exploit of sorts was found in ChangeTip's system.
We were interested in exactly how, so we caught up with Adam Guerbuez who granted us an exclusive interview:
Adam Guerbuez: Well I have always had a passion for testing and exploring the vulnerablities within different websites. With ChangeTip, I realised that they did not have a word filter list on their "custom moniker" feature, that allows any user to assign a monetary value to any word. The user then simply can tip others while using that word and the reciepient of the tip gets the amount that you assigned to it.
For example: you can send someone a tip for a "cup of coffee" and the person will get a couple of dollars if you assign $2 to that moniker. So I decided to try to assign a value to the word "Dollar", however I never expected that the people who built ChangeTip would have overlooked adding that word to the filtered word list. Not only was "Dollar" not on their list, but there was no list at all, any words are allowed and this just seemed very insecure.
So I brought it up to the company officials early in 2015 after I made some tweets using custom monikers like "Dollar" and others I created. The response? I was asked to not use such custom monikers and I just assumed that they were going to add the most obvious ones to a filtered wordlist at that point.
Fast forward many months later, November 23rd I had been trying to close a large promotional contract with a new client who asked me to show him what type of method I could deploy on Twitter to turn heads worldwide. I replied "Give me five minutes and I will show you." So I logged into my Changetip account and was going to create a controversial custom moniker and use it to send tips to many high ranking celebrities and government officials that was sure to turn heads.
By chance I tried to use "Dollar" thinking that ChangeTip had more than eight months to fix the issue, but to my ultimate surprise, I was able to send tips out with it and so I did. The rest is history.
BFG: So how did ChangeTip react this time?
AG: Well, I recieved an email from Nick Sullivan of ChangeTip after I had sent out all the tweets. He had said that the tips I was sending caused several team members to demand that my account be banned because my actions are hurting the ChangeTip brand.
Then a second email followed where they refrenced the tip that I sent to @magicaltux (Mark Karpeles) stating the following:
We’re rolling forward with the ban - as your behavior is a violation of this section of our terms of service: Is harmful, fraudulent, deceptive, threatening, harassing, defamatory, obscene, or otherwise objectionable; Jeopardizes the security of your ChangeTip account or anyone else’s (such as allowing someone else to log in to the Services as you)
Clearly they were angry that I may have offended the former owner of MtGOX when I tipped him for his prison canteen.
BFG: Do you think it was reasonable that they banned you for this?
AG: I am not going to debate their ruleset for using their platform, they run it as they see fit. They have still not fixed the custom moniker issue and I have seen several other people copying what I did now. Clearly they do not see fit to address that simple issue and banning my account from their service was more convienient.
End of interview.
We think that people who explore systems and find holes should be rewarded for finding problems, not punished. Adam had his fun but for now he's no longer allowed to use ChangeTip
Bitcoin Futures Blog prefers to use ProTip, an opensource decentralised tipping solution. We don't believe that people should rely on VC-funded centralised solutions. It is much more in the spirit of bitcoin to empower individuals to do as they want.
Remember to follow @AdamGuerbuez on Twitter, there's sure to be more antics from him in the future!
Have you found any interesting flaws in the systems of Bitcoin services? Contact us and we may feature you with an interview to explain it too!