playing for fun with <=IE7

2007-10-15T00:00:00
ID SECURITYVULNS:DOC:18193
Type securityvulns
Reporter Securityvulns
Modified 2007-10-15T00:00:00

Description

playing for fun with <=IE7 Impact: who knows ... Fix Available: no


1) Bug 2) Proof of concept 3)Conclusion

====== 1) Bug ====== it's possible to bypass the extension filter of <=IE7 this can result by downloading an arbitrary exe file

===== 2)proof of concept ===== let's take this exemple : http://dams083.free.fr/tmp/putty.exe this is simply putty . you click on this and then you will be prompted for downloading the file. but what about if we do : http://dams083.free.fr/tmp/putty.exe?1.txt ... the .exe is showed. now let's go a bit ahead : http://dams083.free.fr/tmp/putty.exe?1.cda wow my .exe is downloaded directly and located in temporary files ( and """opened""" by windows media player). works with theses extension : .log .dif .sol .htt .itpc .itms .dvr-ms .dib .asf .tif etc ... ===== 5) Conclusion ===== this is very funny , because actually it only works for .exe extensions.

.COM , .PIF , etc you CANT do this. ( overwrite the extension , and then bypass the filter) i guess we can wonder what the heck.

regards laurent gaffié