full-disclosure - openssh remote exploit

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Message-ID: <200309171220.45372.adeon@tlen.pl>
From: adeon at tlen.pl (Adam Dyga)
Subject: openssh remote exploit

There is also one little bug in the code, look below.

|
| void *
| buffer_append_space(Buffer *buffer, u_int len)
| {
|         void *p;
|
|         if (len > 0x100000)
|                 fatal("buffer_append_space: len %u not supported", len);
|
|         /* If the buffer is empty, start using it from the beginning.
| */
|         if (buffer->offset == buffer->end) {
|                 buffer->offset = 0;
|                 buffer->end = 0;
|         }
| restart:
|         /* If there is enough space to store all data, store it now.
| */
|         if (buffer->end + len < buffer->alloc) {
[...]

The comparision should be

	if (buffer->end + len <= buffer->alloc) {

because buffer->end is not an offset of last byte in buffer, but it's an 
offset of first byte _afer_ the last byte in buffer. Anyway, this is not a 
security flaw.

--
Greets
adeon