This clever dongle stops attackers sneaking into your HDMI port
A new dongle has been developed to prevent cybercriminals from using the HDMI port as a means of compromising target endpoints (opens in new tab),
The so-called HDMI firewall blocks all communication going in and out of the HDMI port that is not directly related to audio or video. Each HDMI port requires a new dongle, but can be easily reconfigured to fit different ports.
The dongle was designed by a “KingKevin” who uploaded the project to the source code repository CuVoodoo git.
switching dongles around
Of course, actually deploying the dongle would be no easy feat for someone without a fair amount of expertise.
To use a dongle, one must first program it to fit the port it is being implemented on. This means copying Extended Display Identification Data (EDID) information, including data such as supported resolutions. Users can read this data from the endpoint with an I2C-based Display Data Channel (DDC) interface.
The next step is to write the EDID data into the HDMI firewall’s EEPROM, which comes with a physically detachable security tab that locks the connector’s EEPROM from future writes.
In order to move the dongle to a new device, users must once again disable write protection by inserting a solder blob across two pads on the device, rewriting it with the new port’s EDID data. and re-enable protection by removing the connecting solder. two pads.
as explained by Tom’s Hardware, an HDMI connector allows the passthrough of more than just audio and video data. Some parallel protocols are transferring additional data, including high-bandwidth digital content protection, or HDCP. This protocol ensures that the data passing through the port is not copied in transit,
Other notable mentions include hot-plug detection (HPD), and consumer electronics control (CEC). The latter is relatively popular, as it allows remote controls and other gadgets to control devices.
via Tom’s Hardware