Please contact me at security+riju@radian.codes if you find any way to:

• Take down Riju without using a large number of concurrent sessions.
• View or interfere with another user's session.
• Tamper with the Riju server.

Although I work on Riju in my free time, I take security seriously, so I will do my best to get back to you in less than a week, and to correct the vulnerability as soon as possible (I will let you know the likely timeline by email).