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BNC IRC Proxy Buffer Overflow Vulnerability

BNC's IRC Proxy is used as a gateway to an IRC server.

A buffer stores a username which arguments the program's USER command. User-supplied input to this buffer is improperly checked for length.

As a result, the excessive data copied onto the stack can overwrite critical parts of the stack frame such as the calling functions' return address. Since this data is supplied by the user it can be crafted to alter the program's flow of execution.

If properly exploited, this can yield root privilege to the attacker.