[Exploit + fix]Lets hack: Stack subclass skills ( Race condition exploit ).

[Xanderॐ]

wont work that way cause l2j uses a lock on subclass if i remember correctly. When something wants to change the class, it must wait in that lock for its turn.

[PwNNNz0r.^]

wont work that way cause l2j uses a lock on subclass if i remember correctly. When something wants to change the class, it must wait in that lock for its turn.

damn >.<

anyway if i'll ever start l2 again i'll try ur way :P

[mfausb]

no, because you do not kill the mob, someone from your party does

 

Add another simple check for party members maybe being currently in combat.

[Xanderॐ]

Anyway those conditions ( l2j was doing fixes that way in the past ) are not the right way to fix problems. A problem can lead to several exploits, blocking the exploit, wont fix the problem. But taking care of the problem itself, will fix all exploits related to them. When i went in some br interlude server some weeks ago, they had some protection ( l2jbrazil ) that you are not allowed to have equiped weapon when you change subclass. Obvious stupid is obvious :) Those checks can be bypassed, the solution is to lock the right function that handles the skill awarding in different cases.

[mfausb]

Anyway those conditions ( l2j was doing fixes that way in the past ) are not the right way to fix problems. A problem can lead to several exploits, blocking the exploit, wont fix the problem. But taking care of the problem itself, will fix all exploits related to them. When i went in some br interlude server some weeks ago, they had some protection ( l2jbrazil ) that you are not allowed to have equiped weapon when you change subclass. Obvious stupid is obvious :) Those checks can be bypassed, the solution is to lock the right function that handles the skill awarding in different cases.

 

And who guarantees that your possible fix doesnt create (new) exploits as well? :D

[Xanderॐ]

Nobody :) Im human too. Mistakes are poart of life.

[+cs.tribal]

lol!

it's new. never shared before here!

BUT... a friend discovered this one 1 or 2 years before and we decided not telling it to anyone on web so it wouldnt be fixed by anyone!

but now......dmn you! :P

 

btw.sharing it is allright. but why how to fix it?

[Xanderॐ]

A way i propose is using a lock object that gets locked by both the two methods ( setActiveSubclass and levelUp ) so as they cant race together. Or even using the existing subclass lock they have ( i think ) in l2j. Just try to lock it when getting level up.

 

The idea behind going inside an exploit and figuring how it works is to help us discover more by understanding the mechanisms behind exploits. Btw did you guys find it by chance, just by experimenting with ingame actions ? :)

[+cs.tribal]

The idea behind going inside an exploit and figuring how it works is to help us discover more by understanding the mechanisms behind exploits. Btw did you guys find it by chance, just by experimenting with ingame actions ? :)

the main idea came to my friend and then we tried it and really worked!!! :D

[joello]

gg lol. Hopefully it doesn't get fixed anytime soon =)