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An informal review of CTF abuse

gynvael.coldwind.pl

1–10 of 45 posts

Re: An informal review of CTF abuse

#2
>However there are stories of teams going a step further and hacking home routers from random IPs located in various countries. I guess that's trading in ethics and legality for CTF points.

Is finding a single proxy in a country that hard that you need to do that? I would assume proxy lists including each country would already exist.

Re: An informal review of CTF abuse

#3
> There were probably multiple common logic bugs. However one that sticks out in my memory was when the submission system would first check if the team already submitted that flag (fast check in session) and if not, it would check the flag in the database (slow), award points (slow), and finally add the flag to the session (fast). Yup, that's a race condition.

How is "insert into found_flag (team_id, flag_id, found_at) values ($1, $2, now()) on conflict do nothing" slower than this 4 step race-condition-prone operation? (To get the score, "select count(1) from found_flag where team_id=$1".) You don't even need transactions for this, as long as you can't transition from found to not found somehow ("delete from found_flag where team_id=$1 and flag_id=$2").

The only problem I see with this is where validating the correct answer is expensive; without another piece of data to show that validation has started, you can overload the checker by submitting your answer before the first validation routine succeeds. But that is also easy to track, with a timeout even, and you still don't need transactions.

Re: An informal review of CTF abuse

#6

Would be nice if there was the briefest description about what CTF means here, since I expected it to be about gaming (ie Team Fortress) https://www.enisa.europa.eu/news/enisa-news/capture-the-flag...

As far as I understand it's competitive hacking/security

which requires really solid theoretical knowledge and hands-on experience from various computer related topics like:

cryptography, reverse engineering, web, low lvl programming, operating systems, networks, protocols, etc, etc.

Top competitors tend to work at e.g Google for Project Zero or other big institutions like CERT (https://en.wikipedia.org/wiki/Computer_emergency_response_te...) or Banks

Re: An informal review of CTF abuse

#7
>(or rather: fun factor after a couple of years passed and folks stopped being annoyed or down right furious at the perpetrators)

Poor sports, I’ve always struggled to understand people who’d partake in hacking competitions and then get upset because someone got onto their computer and took all the flags.

Re: An informal review of CTF abuse

#8
I've been playing shooters for almost 30 years now, and that includes a lot of CTF on top of tons of duel and TDM. Quake, UT, TF2 (just got back to it after a decade).

That said, I have no idea what this guy is talking about. I thought he was talking about gaming but the more I read, the more confused I get. Especially the facebook part. What is going on here?

edit: thanks, Retr0id

Re: An informal review of CTF abuse

#10
post #8

I've been playing shooters for almost 30 years now, and that includes a lot of CTF on top of tons of duel and TDM. Quake, UT, TF2 (just got back to it after a decade). That said, I have no idea what this guy is talking about. I thought he was talking about gaming but the more I read, the more confused I get. Especially the facebook part. What is going on here? edit: thanks, Retr0id

https://ctftime.org/ctf-wtf/
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