    async def ignore(self, ctx, command: str.lower):
        """
        Ignore or unignore the specified action.

        The bot will no longer respond to these actions.
        """
        try:
            custom = await self.config.guild(ctx.guild).get_raw("custom", command)
        except KeyError:
            custom = NotImplemented
        if custom is None:
            await self.config.guild(ctx.guild).clear_raw("custom", command)
            await ctx.send("I will no longer ignore the {command} action".format(command=command))
        else:
            await self.config.guild(ctx.guild).set_raw("custom", command, value=None)
            await ctx.send("I will now ignore the {command} action".format(command=command))

The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.