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Belkin Wemo Home Automation devices contain multiple vulnerabilities

Vulnerability Note VU#656302

Original Release Date: 2014-02-18 | Last Revised: 2014-07-29

Overview

Belkin Wemo Home Automation devices contain multiple vulnerabilities.

Description

CWE-321: Use of Hard-coded Cryptographic Key - CVE-2013-6952

Belkin Wemo Home Automation firmware contains a hard-coded cryptographic key and password. An attacker may be able to extract the key and password to sign a malicious firmware update.

CWE-494: Download of Code Without Integrity Check - CVE-2013-6951
Belkin Wemo Home Automation devices do not have a local Certificate store to verify the integrity of SSL connections.

CWE-319: Cleartext Transmission of Sensitive Information - CVE-2013-6950
Belkin Wemo Home Automation firmware distribution feed does not use SSL encryption.

CWE-441: Unintended Proxy or Intermediary ('Confused Deputy') - CVE-2013-6949
Belkin Wemo Home Automation devices use STUN & TURN protocols. An attacker with control of one Wemo device may be able to use the STUN & TURN protocols to relay connections to any other Wemo device.

CWE-611: Improper Restriction of XML External Entity Reference ('XXE') - CVE-2013-6948
Belkin Wemo Home Automation API server contains a XML injection vulnerability. The peerAddresses API can be attacked through XML injection, which may reveal the contents of system files.

Additional details may be found in the IOActive advisory.

Impact

A remote unauthenticated attacker may be able to sign malicious firmware, relay malicious connections, or access device system files to potentially gain complete access to the device.

Solution

Update Apps and Firmware

Users with the most recent firmware release (version 3949) are not at risk for malicious firmware attacks or remote control or monitoring of WeMo devices from unauthorized devices. Belkin urges such users to download the latest app from the App Store (version 1.4.1) or Google Play Store (version 1.1.2) and then upgrade the firmware version through the app.

Specific fixes Belkin has issued include:

1) An update to the WeMo API server on November 5, 2013 that prevents an XML injection attack from gaining access to other WeMo devices.

2) An update to the WeMo firmware, published on January 24, 2014, that adds SSL encryption and validation to the WeMo firmware distribution feed, eliminates storage of the signing key on the device, and password protects the serial port interface to prevent a malicious firmware attack

3) An update to the WeMo app for both iOS (published on January 24, 2014) and Android (published on February 10, 2014) that contains the most recent firmware update.

Vendor Information

656302
 
Expand all

Belkin, Inc. Affected

Notified:  October 24, 2013 Updated: February 20, 2014

Status

Affected

Vendor Statement

Belkin has corrected the list of five potential vulnerabilities affecting the WeMo line of home automation solutions that was published in a CERT advisory on February 18. Belkin was in contact with the security researchers prior to the publication of the advisory, and, as of February 18, had already issued fixes for each of the noted potential vulnerabilities via in-app notifications and updates. Users with the most recent firmware release (version 3949) are not at risk for malicious firmware attacks or remote control or monitoring of WeMo devices from unauthorized devices. Belkin urges such users to download the latest app from the App Store (version 1.4.1) or Google Play Store (version 1.1.2) and then upgrade the firmware version through the app.

Specific fixes Belkin has issued include:

1) An update to the WeMo API server on November 5, 2013 that prevents an XML injection attack from gaining access to other WeMo devices.

2) An update to the WeMo firmware, published on January 24, 2014, that adds SSL encryption and validation to the WeMo firmware distribution feed, eliminates storage of the signing key on the device, and password protects the serial port interface to prevent a malicious firmware attack

3) An update to the WeMo app for both iOS (published on January 24, 2014) and Android (published on February 10, 2014) that contains the most recent firmware update

Vendor Information

We are not aware of further vendor information regarding this vulnerability.


CVSS Metrics

Group Score Vector
Base 7.8 AV:N/AC:M/Au:N/C:P/I:C/A:N
Temporal 5.8 E:POC/RL:OF/RC:UR
Environmental 1.5 CDP:ND/TD:L/CR:ND/IR:ND/AR:ND

References

Acknowledgements

Thanks to Mike Davis of IOActive for reporting these vulnerabilities.

This document was written by Jared Allar.

Other Information

CVE IDs: CVE-2013-6948, CVE-2013-6949, CVE-2013-6950, CVE-2013-6951, CVE-2013-6952
Date Public: 2013-12-09
Date First Published: 2014-02-18
Date Last Updated: 2014-07-29 22:25 UTC
Document Revision: 50

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