HexBrain

Slack · Report #210654

Bypass to postMessage origin validation via FTP

Validstatus
highseverity
15upvotes
21 Apr 2017disclosed

Summary

@a1kmm- discovered a bypass to our postMessage origin check, wherein an attacker with existing MITM capabilities could use FTP to bypass validation and view XOXS tokens of victims on the local network. This was related to, and investigated at the same time as, a previous report. This issue is now resolved and was not exploited. Thanks @a1kmm-!

How it was found

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