There is no single "solid paper" (academic or research whitepaper) specifically titled or centered on a "TNT323DAC firmware patched" vulnerability or exploit in common public security repositories
Enhance Security: Protect your network from vulnerabilities.
Test the Calibration Mode
Power the module via its normal power input (24V DC). Short TP7 to GND before applying power. Open a serial terminal at 115200 baud. You should see the message: "TNT323DAC Patched v2.1 - Calibration Mode Active"
Enabling features like VoIP or advanced routing that were disabled by the provider. TP-Link Community Risks of Using Patched Firmware