Wietse Venema schrieb:
> Oliver Block:
>
>> Hello everyone,
>>
>> these days you can read dozens of articles that implitely claim that
>> the following code will produce more than one mail message at a time
>> if used by a malicous user.
>>
>> I doubt that it is true, but I'd like to ask here, because you know
>> your mta better than I. The c code to access postdrop/sendmail is the
>> following:
>>
>> ...
>>
>> errno = 0;
>> sendmail = popen(sendmail_cmd, "w");
>>
>> if (sendmail) {
>>
>> ...
>>
>> fprintf(sendmail, "To: %s\n", to);
>> fprintf(sendmail, "Subject: %s\n", subject);
>>
>
> If the to or subject are taken from an untrusted user, they may
> contain contain newlines, MIME headers, a new body, and other MIME
> headers that prevent your real message from being displayed.
>
>
I understand that. And this should be considered. In the example above
the authors decided to leave the responsibility to the programmer that
relies on the code above.
But what about the "." and that an mta will create two messages in a row
when send over a pipe? Does this work with postdrop?
Best regards,
Oliver Block
