Got *Bounty* with Account takeover (ATO ) Unicode-Case Mapping Collision !

Shaurya Sharma
Mar 5, 2020 · 2 min read
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Hey hunters ! Recently I discovered a Unicode-Case Mapping Collision vulnerability on a private program.

Unicode exceptionally complex. Few people know all the tricks: from invisible characters and control characters to surrogate pairs and combined emojis (when adding two characters you get a third).

As the vulnerability is still not patched yet so I’m denoting the website with “” in this blog

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I have just registered my own domain to exploit a security flaw in forgot password process to gain access to an account that belongs to a privileged user.


In this case, I used the Turkish character ‘ı’ (‘i’ without a dot), which is translated into Latin ‘i’, so that the postal address Test@xyz. ın after processing turns into

  • Successfully created a domain xyz. ın (Without the dot)
  • Created Free email from Google G-Suite trial pack and named it “Admin@xyz. ın”
  • Created an account on “” with the malicious email address as “admin@xyz.ın”
  • Logged out from that account >> logged in “admin@xyz.ın” and clicked on Forget Password.
  • Intercepted the request>> And the input reflecting in UPPER CASE
  • The DB found replaced the malicious user with the correct one and triggered a password reset token on the malicious email address.
  • Successfully changed the password of the admin user, and got the bounty!!

Such collisions can be found on all Unicode planes: here is the complete list .

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#HappyHunting #BugBounty #2020 #CyberVerse

Cyber Verse

You are under survillence.

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