1 | initial version |
First up, if a password comes up in clear text in network traffic, there are bigger problems.
That being said, telnet is still a thing, so there's that.
In this case there's little else to do than to go into (a copy of) the file with a hex editor, search for the password, replace the characters and save the file. Now when loaded back into Wireshark, there will be complaints about checksums that are incorrect. You either make a note in the packet saying that the packet is tweaked, or you may go into the file again, and touch up the checksums as well.