Monday, February 18, 2008

Mono trickery


I always spot the best bugs during coding. While coding tjmd5 (see last posting) I ran across
an interesting mono feature. For each 'foo' C# file that it compiles it lookups 'foo.so'
in /usr, /usr/lib etc directories and 'foo.so.la' in the cwd. This can be abused to execute
arbitrary code while someone is just compiling an C#-file. I am not sure about the impact since
you can say that the dude is executing the .exe after he was compiling it. Well.
Depending on the comments you all make I will decide whether this is something to tell Miguel :-)

Trapper John MD5

During hackweek in Nuremberg I lifted my C#-skills and wrote a MD5 based filesystem
and web integrity checker from scratch. In .NET, from scratch means you plug a few classes
and API calls together and get a complex application in 100 lines :-)
C# is fun coding nevertheless. Never heared again from tripwire, one of my faves
back in the 90's. You can download trapper john md5 here.