[gopher] Re: Fwd: Bug#82602: gopherd: [SECURITY] gopherd is dangerous

[John Goerzen <jgoerzen@xxxxxxxxxxxx>]

severity 82602 fixed
thanks

I have found the remaining bugs listed in this report, have committed
changes to CVS, and am building 2.3.1-9 for upload right now.

[ actually it's uploaded now ]

Thanks.  Would you like write access to CVS so that you can fix these
yourself?  I think that would be great.  Please mail me your PGP or
GPG public key, and I'll encrypt account details to you.

-- John

Aaron Lehmann <aaronl@xxxxxxxxxxx> writes:

> From: aaronl@xxxxxxxxxxx
> Subject: Bug#82602: gopherd: [SECURITY] gopherd is dangerous
> To: submit@xxxxxxxxxxxxxxx
> Date: Tue, 16 Jan 2001 22:57:23 -0800
> 
> Package: gopherd
> Version: 2.3.1-8
> Severity: grave
> 
> 
> First off:
> 
> $ egrep -r '(sprintf|strcpy|strcat)' * | wc -l
>     539
> 
> *shudder*
> 
> 
> Here are a few particular cases of fixed-size buffers that I think may
> currently be security risks:
> 
>      char buf[256];
> ...
>       if (dochroot)
>            sprintf(buf, "%s '%s'", decoder, pathname);
>       else
>            sprintf(buf, "%s '%s/%s'", decoder, Data_Dir, pathname);
> 
> As far as I can tell, neither decoder nor pathname is regulated in
> size at all.
> 
> Here's another favorite:
>      char         longname[256];
> ...
>            sprintf( longname, "%s  [%s%s%s, %ukb]", stitle,
>               cdate+8,cdate+4,cdate+22, (statbuf.st_size+1023) / 1024);
> 
> Even if the length of stitle was regulated (which I doubt), it would
> most likely be regulated to 256 bytes, which would be just as
> disasterous.
> 
> Oh, and you had better hope that the path to your Data_Dir is < 256 chars:
>      char tmpstr[256];
> ...
>             strcpy(tmpstr, Data_Dir);
> 
> Data_Dir is _not_ regulated in size:
>       Data_Dir = strdup(argv[optind]);
> ...
>       Data_Dir = strdup(DATA_DIRECTORY);
> 
> How about this:
> 
>      if ((titlep = strcasestr(buf, "<TITLE>")) != NULL) {
>       char *endtitle;
>       char titletemp[256];
> 
>       titlep += 7;
>       if ((endtitle = strcasestr(titlep, "</TITLE>")) != NULL) {
>            strncpy(titletemp, titlep, (endtitle-titlep));
>            titletemp[endtitle-titlep] = '\0';
> 
> So, list a directory containing a .html document with a title > 256
> chars and you're likely to smash the stack.
> 
> I could go on and on. My reccomendation to the gopherd maintainer is
> to throw out all of this code and write a more modern, secure
> implentation from scratch. This is the worst C code I have ever read.
> 
> 
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> 
> ----------
> 
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> 

-- 
John Goerzen <jgoerzen@xxxxxxxxxxxx>                       www.complete.org
Sr. Software Developer, Progeny Linux Systems, Inc.    www.progenylinux.com
#include <std_disclaimer.h>                     <jgoerzen@xxxxxxxxxxxxxxxx>