{"id":484,"date":"2013-09-09T04:39:55","date_gmt":"2013-09-09T04:39:55","guid":{"rendered":"http:\/\/www.gironsec.com\/blog\/?p=484"},"modified":"2013-09-09T21:49:42","modified_gmt":"2013-09-09T21:49:42","slug":"raw-tcp-packet-builder-sender-in-c-sharp","status":"publish","type":"post","link":"https:\/\/www.gironsec.com\/blog\/2013\/09\/raw-tcp-packet-builder-sender-in-c-sharp\/","title":{"rendered":"Raw TCP Packet Builder \/ Sender in C#"},"content":{"rendered":"<p>Hello again people!<\/p>\n<p>I&#8217;ve been busy lately with my awesome job giving me free time to code things up. I&#8217;ve constructed a raw TCP packet builder in C# for the hell of it. I coded this up using winpcap to test a topic I saw at Defcon this year. It was said a vulnerability exists in the TCP stack for Windows and Linux having to do with the &#8216;window length&#8217; bit in a TCP packet. Specifically if you flood a target with TCP packets full of data, but set the &#8216;windows length&#8217; bit to 0, you are telling the host that your reserves are full and need the destination&#8217;s stack to hold the data for a while. <\/p>\n<p>I could have done with with scapy or some other interpreted language, but I wanted to make a tool with a dummed down interface any idiot could use. C# to the rescue for that.<\/p>\n<p>Here is what it looks like:<br \/>\n<a href=\"http:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/dos-tool.png\"><img decoding=\"async\" loading=\"lazy\" src=\"http:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/dos-tool.png\" alt=\"dos tool\" width=\"582\" height=\"544\" class=\"alignnone size-full wp-image-496\" srcset=\"https:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/dos-tool.png 582w, https:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/dos-tool-300x280.png 300w\" sizes=\"(max-width: 582px) 100vw, 582px\" \/><\/a><\/p>\n<p>It works for testing the vulnerability because it sets the length to 0 no matter what TCP flags you set or what payload you give it. It&#8217;s also great for syn flooding your neighbors. <\/p>\n<p>This is an alpha version. The tool has bugs, but it works. Be sure to install winpcap (and START the service) for this to work.<br \/>\nSource \/Binary is here:<br \/>\n<a href=\"http:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/PacketMaker.7z\">PacketMaker<\/a><br \/>\nThe password is &#8216;gironsec&#8217; without quotes.<\/p>\n<p>Don&#8217;t do anything I wouldn&#8217;t do.<br \/>\n<a href=\"http:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/Mario-glitch.gif\"><img decoding=\"async\" loading=\"lazy\" src=\"http:\/\/www.gironsec.com\/blog\/wp-content\/uploads\/2013\/09\/Mario-glitch.gif\" alt=\"Mario-glitch\" width=\"249\" height=\"212\" class=\"alignnone size-full wp-image-497\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Hello again people! I&#8217;ve been busy lately with my awesome job giving me free time to code things up. I&#8217;ve constructed a raw TCP packet builder in C# for the hell of it. I coded this up using winpcap to test a topic I saw at Defcon this year. It was said a vulnerability exists [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[4,6],"tags":[66,63,65,64],"_links":{"self":[{"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/posts\/484"}],"collection":[{"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/comments?post=484"}],"version-history":[{"count":4,"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/posts\/484\/revisions"}],"predecessor-version":[{"id":500,"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/posts\/484\/revisions\/500"}],"wp:attachment":[{"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/media?parent=484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/categories?post=484"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gironsec.com\/blog\/wp-json\/wp\/v2\/tags?post=484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}