Perixx Computer PERIDUO-710W Insufficient Protections

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Advisory ID: SYSS-2016-045  
Product: PERIDUO-710W  
Manufacturer: Perixx Computer GmbH  
Affected Version(s): Part No. KG-1027  
Tested Version(s): Part No. KG-1027  
Vulnerability Type: Insufficient Protection of Code (Firmware) and   
Data (Cryptographic Key)  
Risk Level: Medium  
Solution Status: Open  
Manufacturer Notification: 2016-05-27  
Solution Date: -  
Public Disclosure: 2016-07-29  
CVE Reference: Not yet assigned  
Authors of Advisory: Matthias Deeg and Gerhard Klostermeier (SySS GmbH)  
  
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Overview:  
  
PERIDUO-710W is a wireless desktop set consisting of a mouse and a  
keyboard.  
  
The manufacturer describes the product as follows (see [1]):  
  
"PERIDUO can create flexible, convenient and wireless working  
environment with its design. PERIDUO offers a reliable 2.4GHz high  
frequency penetration, low interference, and omni-directional signal  
transmissions with 10Meters meters [sic] receiving distance."   
  
Due to the insufficient protection of the flash memory of the keyboard,  
an attacker with physical access to the wireless keyboard has read  
and write access to the firmware and the used cryptographic key.  
  
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Vulnerability Details:  
  
The SySS GmbH found out that the embedded flash memory of the wireless  
keyboard PERIDUO-710W can be read and written via the SPI interface of  
the used transceiver with an embedded microcontroller nRF24LE1H, as the  
flash memory is not protected by the offered read back protection  
feature (RDISMB - Read DISable Main Block).  
  
Thus, an attacker with physical access to the keyboard and transceiver   
can simply read and write the SPI-addressable code and data flash memory.   
Due to the use of nRF24 transceiver versions with one-time programmable   
memory, write access is limited in such a way that a set 1 bit can be   
changed to a 0 bit but not vice versa.  
  
The AES cryptographic key used by the PERIDUO-710W keyboard is  
accessible via the SPI interface.   
  
By having read and write access to the code and data flash memory, an  
attacker can either extract the cryptographic key, for instance to  
perform further attacks against the wireless communication, or modify  
the firmware or the cryptographic key in a restricted way due to the  
used one-time programmable memory.  
  
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Proof of Concept (PoC):  
  
The SySS GmbH could successfully read the contents of the code and data  
flash memory of the PERIDUO-710W keyboard using the hardware tool Bus  
Pirate [3] in combination with the software tool nrfprog [4].  
  
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Solution:  
  
The SySS GmbH is not aware of a solution for this reported security  
vulnerability.  
  
For further information please contact the manufacturer.  
  
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Disclosure Timeline:  
  
2016-05-27: Vulnerability reported to manufacturer  
2016-06-06: Vulnerability reported to manufacturer again  
2016-07-29: Public release of the security advisory  
  
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References:  
  
[1] User manual for Perixx PERIDUO-710W  
http://perixx.com/en/service/Perixx_Manual/DUO/PERIDUO-710_manual.pdf  
[2] Product website for Perixx PERIDUO-710W  
http://perixx.com/en/products/perixx-pro-11.html  
[3] Website of Bus Pirate hardware tool  
http://dangerousprototypes.com/docs/Bus_Pirate  
[4] nrfprog Github repository  
https://github.com/nekromant/nrfprog  
[5] SySS Security Advisory SYSS-2016-045  
https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2016-045.txt  
[6] SySS Responsible Disclosure Policy  
https://www.syss.de/en/responsible-disclosure-policy/  
  
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Credits:  
  
This security vulnerability was found by Matthias Deeg and Gerhard  
Klostermeier of the SySS GmbH.  
  
E-Mail: matthias.deeg (at) syss.de  
Public Key: https://www.syss.de/fileadmin/dokumente/Materialien/PGPKeys/Matthias_Deeg.asc  
Key fingerprint = D1F0 A035 F06C E675 CDB9 0514 D9A4 BF6A 34AD 4DAB  
  
E-Mail: gerhard.klostermeier (at) syss.de  
Public Key: https://www.syss.de/fileadmin/dokumente/PGPKeys/Gerhard_Klostermeier.asc  
Key fingerprint = 8A9E 75CC D510 4FF6 8DB5 CC30 3802 3AAB 573E B2E7  
  
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Disclaimer:  
  
The information provided in this security advisory is provided "as is"   
and without warranty of any kind. Details of this security advisory may   
be updated in order to provide as accurate information as possible. The  
latest version of this security advisory is available on the SySS Web   
site.  
  
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Copyright:  
  
Creative Commons - Attribution (by) - Version 3.0  
URL: http://creativecommons.org/licenses/by/3.0/deed.en  
  
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