Re: Windows 95 Serv-U FTP bug

Alan Thew (Alan.Thew@liverpool.ac.uk)
Fri, 06 Feb 1998 18:30:55 +0000

The author (I'm just a customer, no financial stake etc. sent with
permission) says:

"I've run the program, and it does indeed kill Serv-U on Win95 on a fast
link. From the looks of it sofar it seems the Win95 socket stack is to
blame. It never even goes into actual Serv-U code when it crashes, but
stays in system drivers."

--
Alan Thew                                       alan.thew@liverpool.ac.uk
Computing Services,University of Liverpool      Fax: +44 151 794-4442


On Thu, 5 Feb 1998, tl wrote:


> This program doesn't do anything to my Serv-U program.  I can see the
> garbage flooding, however when I break out of serv-who.c, serv-u continues
> to run normally without any crash or system slowdown.  I'm running win95
> osr2 on a PPro 150, and ServU version 2.0c 32bit.  This is an older version
> so perhaps that's the reason ..
>
> -----Original Message-----
>
>
> >Hello,
> >After reading an earlier message, Windows 95/NT War FTPD 1.65 Buffer
> >Overflow, I thought I might play around with some other Windows ftp
> >servers.  One problem I found was in Serv-U FTP by Cat-Soft
> ><http://www.cat-soft.com>.  After you connect instead of sending the normal
> >USER then PASS, you can send garbage.  And if you send alot of garbage at a
> >high speed Serv-U will stop responding to mouse clicks and after a short
> >amount of time will crash and give you this:
> >
> >SERV-U32 caused a stack fault in module KERNEL32.DLL at 014f:bff9a08c.
> >Registers:
> >EAX=005e2084 CS=014f EIP=bff9a08c EFLGS=00000246
> >EBX=17bf0514 SS=0157 ESP=005e2080 EBP=005e20d4
> >ECX=005e2098 DS=0157 ESI=81628c70 FS=2347
> >EDX=ffffffff ES=0157 EDI=0000ffff GS=0000
> >Bytes at CS:EIP:
> >5e 8b e5 5d c2 10 00 64 a1 00 00 00 00 55 8b ec
> >Stack dump:
> >00000001 c00000fd 00000000 00000000 bff9a08c 00000000 01570157 01870028
> >17bf0b6a c10fabe8 16c70001 80dc0014 16e73a45 00040000 02000000 bff97fdc
> >
> >Why it does this I have no idea.  It only acts this way in the windows 95
> >version.  Under NT the cpu usage goes up to 100%, but no crash.  Alot of
> >times even after the crashed Serv-U has closed, Windows is still slow to
> >non responsive.
> >
> >And here is the program I used, not pretty but it works:
> >
>