DNS TXT Records: Exploiting the 64KB Limit
2025-09-20
Contrary to popular belief, DNS TXT records aren't limited to 255 bytes. By leveraging TCP and custom JSON parsing, a developer bypassed this limit, transmitting up to 64KB of data. A custom Go server and Google Public DNS's JSON API were used to transmit a large binary file within a TXT record. This experiment showcases a clever hack and raises security concerns, particularly regarding potential DNS tunneling attacks.
(dgl.cx)
Tech
TXT record