SSCHADV2011-002 - Cross-Site Scripting vulnerability in Nagios

Trackbacks

Comments

Add Comment

Posted by Stefan Schurtz on Wednesday, March 9. 2011

Advisory:	Cross-Site Scripting vulnerability in Nagios
Advisory ID:	SSCHADV2011-002
Author:	Stefan Schurtz
Affected Software:	Successfully tested on: nagios-3.2.0 / nagios-3.2.3
Vendor URL:	http://www.nagios.org
Vendor Status:	fixed
CVE-ID:	2011-1523
OSVDB-ID:	71059

======================
Vulnerability Description:
======================

This is a Cross-Site Scripting vulnerability

JavaScript can be included in style sheets by using "expression()" (IE only)

==============
Technical Details:
==============

The function "strip_html_brackets" strip > and < from string but it’s not enough to prevent XSS attacks in "statusmap.cgi&layer="

http://site/nagios/cgi-bin/statusmap.cgi?layer=’ style=xss:expression(alert(‘XSS’)) ‘
http://site/nagios/cgi-bin/statusmap.cgi?layer=’ onmouseover="alert(‘XSS’)" ‘

======================
cgiutils.c
======================

[schnipp]
.
.

/* strip > and < from string */

void strip_html_brackets(char *buffer){
        register int x;
        register int y;
        register int z;
        if(buffer==NULL || buffer[0]'x0')
                return;
        /* remove all occurances in string */
        z=(int)strlen(buffer);
        for(x=0,y=0;x<z;x++){
                if(buffer[x]‘<’ || buffer[x]'>')
                        continue;
                buffer[y++]=buffer[x];
                }
        buffer[y++]='x0';
        return;
        }

.
.
[schnapp]

========================
statusmap.c
========================
[schnipp]
.
.

/* we found the layer argument */
         else if(!strcmp(variables[x],"layer")){
                x++;
                if(variables[x]NULL){
                      error=TRUE;
                      break;
                }
                strip_html_brackets(variables[x]);
                add_layer(variables[x]);
                }

.
.
[schnapp]

========================
Problem in "statusmap.c"
========================
[schnipp]
.
.

/* print layer url info */

void print_layer_url(int get_method){
  layer *temp_layer;
    for(temp_layer=layer_list;temp_layer!=NULL;temp_layer=temp_layer->next){
       if(get_method==TRUE)
         printf("&layer=%s",temp_layer->layer_name); <— no "escape_string"        else
         printf("<input type=‘hidden’ name=‘layer’ value=’%s’>n",escape_string(temp_layer->layer_name));

.
.
[schnapp]
=====
Solution:
=====

if(get_method==TRUE)
          /* printf("&layer=%s",temp_layer->layer_name); */
          printf("&layer=%s",escape_string(temp_layer->layer_name));

================
Disclosure Timeline:
================

09-Mar-2011 – informed developers
09-Mar-2011 – post on Nagios Tracker – http://tracker.nagios.org/view.php?id=207

09-Mar-2011 – Release date of this security advisory
10-Mar-2011 – post on BugTraq

10-Mar-2011 – post on Full-disclosure

25-Jul-2001 – fixed in Nagios 3.3.1

====
Credits:
====

Vulnerability found and advisory written by Stefan Schurtz.

=======
References:
=======

http://www.nagios.org
http://www.rul3z.de/advisories/SSCHADV2011-002.txt

http://osvdb.org/show/osvdb/71059

http://www.securityfocus.com/archive/1/516934/30/0/threaded

http://www.tenable.com/plugins/index.php?view=single&id=55163

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2011-1523

Trackback specific URI for this entry

No Trackbacks

Display comments as Linear | Threaded

No comments

October '24

Name

Homepage

Comment

In reply to

To prevent automated Bots from commentspamming, please enter the string you see in the image below in the appropriate input box. Your comment will only be submitted if the strings match. Please ensure that your browser supports and accepts cookies, or your comment cannot be verified correctly.

Enter the string from the spam-prevention image above:

Textile-formatting allowed

You can use [geshi lang=lang_name [,ln={y|n}]][/geshi] tags to embed source code snippets.

Form options

Remember Information?

Subscribe to this entry