A method presented at DerbyCon and BlackHat involves extracting not the bits of the character but the bits of a characters position in a look up table which contains a number of character ascii values---more on this later. This post discusses the conceptual advantages and fundamental drawbacks of the bin2pos method and introduces a new variant I've developed which provides better stability and only requires a maximum of 4 requests per character extraction but imposes some configurational requirements to the target web server.
Saturday, 12 October 2013
Sunday, 30 December 2012
I'll be using the mod_security challenge set up by spiderlabs a about year ago. It may still ring all the mod_sec alarms but the purpose is not to threaten mod_sec---not yet---instead to show what the attack would look like in full swing.