Logitech Unifying receiver
The Logitech Unifying receiver is a small dedicated USB wireless receiver, based on the nRF24L-family of RF devices, that allows up to six compatible Logitech human interface devices (such as mice, trackballs, trackpads, and keyboards; headphones are not compatible) to be linked to the same computer using 2.4 GHz band radio communication. Receivers that are bundled with a Logitech product are paired with the device at the factory. When purchasing a replacement receiver or connecting multiple devices to one receiver, pairing requires the free-of-charge Logitech Unifying software, available for Microsoft Windows and Mac OS X. Although not compatible with Bluetooth, devices pair to Unifying Receivers in a similar way. Peripherals remain paired, and can then be used on systems not supporting the software. Logitech receivers compatible with the Unifying protocol can be identified by the orange Unifying logo, which distinguishes them from Logitech Nano receivers of similar appearance, which pair in a similar manner but only with a single device, without using the Unifying protocol.
Logitech Unifying receivers (LURs) are often included in wireless Logitech keyboard, mouse, and combo sets, and may be purchased separately. Some Logitech peripherals allow a receiver to be stored inside.
Compatibility and useEdit
Each peripheral device can pair to one receiver per profile. While most peripherals only store one profile, newer products such as the Logitech MX Master, MX Anywhere series, and M720 Triathlon allow multiple profiles. These devices can be connected to multiple receivers simultaneously. This allows the use of receivers in several computers, e.g., a desktop and a laptop computer, selecting the computer to use by changing profiles on the mouse. This multi-computer function is further augmented by Logitech Flow (software KVM solution) which is similar to Synergy. For devices without multi-computer support, the receiver and input devices can be moved together from one computer to another, maintaining their paired status after being unplugged, as the pairing information is held in the little USB receiver—this is much simpler than transferring the peripheral from one receiver to another by changing the setup in software, and also avoids the limitation to 45 pairings of older devices. This also allows the use of peripherals on computing devices that do not support Unifying Software, e.g. devices supporting USB OTG with operating systems such as Android: first pair to the receiver on a PC or Mac.
Some older Unifying devices limit the number of allowable pairing changes to a maximum of 45 times. Once the 45th connection is made, it is no longer possible to connect such a device to a different receiver. For users who often switch a Unifying device between multiple PCs or laptops with individual receivers, this connection limit can become an issue. For example, a user who frequently switches a mouse between two receivers (e.g. at work and home) will quickly exhaust the limit of available pairing switches. Logitech advises customers with this issue to contact their Customer Care. Newer devices can switch pairings an unlimited number of times.
Pairing software is available from Logitech for Microsoft Windows and Mac OS X. Wireless devices using the Unifying Receiver are supported since Linux 3.2. Software to manage Unifying devices on Linux is available from third party developers, such as Solaar.
There are many different hardware versions of the unifying receiver. The most common is used for daily use, and is marked  CU-0007 on the metal jacket. CU-0008 is distributed with gaming devices, and features lower latency.
Several security vulnerabilities of the Logitech Unifying system have been reported in 2016 and 2019, and patches released.
MouseJacking and keyjackingEdit
MouseJacking, first reported by Bastille Networks, Inc., is the sending of malicious radio signals (packets) wirelessly to an unsuspecting user through Logitech Unifying wireless technology. The exploit takes advantage of a user's vulnerable Logitech Unifying receiver and unencrypted signals within a range of about 100 meters. Possible exploits include:
- Keystroke injection by either spoofing a paired mouse or keyboard
- Forced pairing
Affected devices and firmwareEdit
|Logitech Wireless Gaming Mouse G900||046d:c081|
|Logitech Wireless Keyboard K360||046d:4004|
|Logitech Multi-Device Wireless Keyboard K370s||046d:4061|
|Logitech Multi-Device Wireless Keyboard K375s||046d:4061|
|Logitech Wireless Touch Keyboard K400r||046d:400e, 046d:4024|
|Logitech Wireless Touch Keyboard K400 Plus||046d:404d|
|Logitech Wireless Solar Keyboard K750||046d:4002|
|Logitech Multi-Device Wireless Keyboard K780||046d:405b|
|Logitech Illuminated Living-Room Keyboard K830||046d:404c, 046d:4032|
|Logitech Performance Wireless Keyboard MK850||046d:4062|
|Logitech Wireless Mouse M335|
|Logitech Zone Touch Mouse T400||046d:4026|
|Logitech Wireless Mouse M545|
|Logitech Wireless Mouse M560|
|Logitech Touch Mouse M600||046d:401a|
|Logitech Touch Mouse T620||046d:4027|
|Logitech Wireless Rechargeable Touchpad T650||046d:4101|
|012.001.00019||Affected by Bastille security issues #1, #2, #3|
|012.003.00025||Affected by Bastille security issues #1, #2, #3|
|<012.005.00028||Affected by Bastille security issues #1, #2, #3, #11, #13|
|012.005.00028||Affected by Bastille security issues #11, #13|
|012.007.00029||Affected by Bastille security issue #13|
|<024.003.00027||Affected by Bastille security issue #2, #3, #11, #13|
|024.003.00027||Affected by Bastille security issue #11, #13|
|024.005.00029||Affected by Bastille security issue #13|
Firmware not affectedEdit
|012.009.00030||Identical to 012.008.00030 but DFU signed|
|024.007.00030||Identical to 024.006.00030 but DFU signed|
For Linux users there are native options to flash and experiment with such as fwupd and MouseJack. However, with these tools a separate firmware binary is still required. Flashing on a Linux host via a hypervisor such as VirtualBox along with a Windows virtual guest image and the Windows Logitech update executable is also possible. If using a Windows virtual guest, it is recommended to have a second available pointing device while the dongle is being updated. The second pointing device may be needed to allow the user to select and enable pass through of the unifying receiver via the hypervisor task bar after executing the firmware updater so that the device is found and updated.
Updating the Unifying receiver firmware to versions RQR12.08 or greater and RQR24.06 or greater can limit some functionality of certain paired devices unless the devices' firmware is also updated.
On July 9, 2019 another set of vulnerabilities was disclosed and documented by a different researcher. A firmware update for Unifying receivers addressing the "Encryption Key Extraction Through USB" vulnerability (CVE-2019-13054/55) was released on 28 August 2019. Some users reported in 2019 that some Unifying devices are still being sold that are vulnerable to the original 2016 MouseJacking attack.
- Newlin, Marc (2016-08-07). "MouseJack device discovery and research tools". Retrieved 2019-07-25.
- Gallegos, Gary. "Gadgets: The Logitech Unifying Receiver (aka "fake bluetooth")". Archived from the original on 4 March 2016.
- "Logitech Unifying Multi-Connect Utility Setup Instructions" (PDF). Logitech.
- "Logitech Unifying Software". Logitech Support + Download. Retrieved 3 October 2019.
- "Android Tablets and Logitech Unifying Devices". Music Tribe. 7 January 2018.
- "Limitations on Unifying devices". Archived from the original on 2019-07-10. Retrieved 2019-07-25.
- Nestor Lopez Casado (2011-09-15). "HID: Add full support for Logitech Unifying receivers". Linux kernel. Retrieved 2019-07-25.
- Solaar on GitHub
- . 2020-08-23. Missing or empty
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- mame82 (2019-07-09). "Summary / Overview of known Logitech wireless peripheral vulnerabilities". Retrieved 2019-07-25.
- "MouseJack Affected Devices". Bastille Networks. Retrieved 2019-07-25.
- Viredaz, Marc (2017-12-22). "RQR12.08 Build 0030". Retrieved 2019-07-25.
- Viredaz, Marc (2017-12-22). "RQR24.06 Build 0030". Retrieved 2019-07-25.
- Viredaz, Marc (2017-12-22). "RQR12.09 Build 0030". Retrieved 2019-07-25.
- Viredaz, Marc (2017-12-22). "RQR24.07 Build 0030". Retrieved 2019-07-25.
- LogiLaurie (2016-07-28). "Logitech Response to Research Findings". Archived from the original on 2019-07-09. Retrieved 2019-07-25.
- "Logitech Unifying Receiver Update". Logitech Support + Download. 28 August 2019.
- Hollister, Sean (2019-07-14). "Why you should really, really update your Logitech wireless dongle". The Verge. Retrieved 2020-01-02.
- Logitech Unifying for Linux: Reverse Engineering and unpairing tool
- Solaar on GitHub - Linux devices manager for the Logitech Unifying Receiver