Overflow in kppp -c option

Date: Wed, 29 Apr 1998 12:39:19 +0200
From: "|[TDP]|" <tdp@psynet.net>
To: BUGTRAQ@NETSPACE.ORG
Subject: Security hole in kppp

  I found an xploitable bug in my kppp application that comes with KDE
env.
Local user can execute malicious code to obtain root access/shell.

gollum:~$ cd /usr/local/kde/bin
gollum:/usr/local/kde/bin$ ls -la kppp
-rwsr-xr-x   1 root     root       262516 Mar 15 01:17 kppp*
( ^- suid!)

gollum:/usr/local/kde/bin$ kppp -h
kppp -- valid command line options:
 -h describe command line options
 -c account_name : connect to account account_name
 -q : quit after end of connection
 -r rule_file: check syntax of rule_file

 I discover that -c option is buggy and root xploitable buffer overflow.


 With 244 or < chars (X's) executes with out problems

 With 245 chars (X's) gives me an error

gollum:/usr/local/kde/bin$ kppp -c
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Virtual memory exceed in `new'

 With 246 or > (until about 1024) chars (X's) cause a core dump :)

gollum:/usr/local/kde/bin$ kppp -c
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Segmentation fault (core dumped)

^^^^^^^^^^^^  Security hole...  Dangerous, isn't it?


 Remove the suid bit or wait for a patch

                                             -=[  [TDP] - H-13 MeMBaH
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