JH/34 Bug 2199: fix a use-after-free while reading smtp input for header lines.
A crafted sequence of BDAT commands could result in in-use memory beeing
- freed.
+ freed. CVE-2017-16943.
+
+HS/03 Bug 2201: Fix checking for leading-dot on a line during headers reading
+ from SMTP input. Previously it was always done; now only done for DATA
+ and not BDAT commands. CVE-2017-16944.
Exim version 4.89
prevent further reading), and break out of the loop, having freed the
empty header, and set next = NULL to indicate no data line. */
- if (ptr == 0 && ch == '.' && (smtp_input || dot_ends))
+ if (ptr == 0 && ch == '.' && dot_ends)
{
ch = (receive_getc)(GETC_BUFFER_UNLIMITED);
if (ch == '\r')
DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
(int)chunking_state, chunking_data_left);
+ /* push the current receive_* function on the "stack", and
+ replace them by bdat_getc(), which in turn will use the lwr_receive_*
+ functions to do the dirty work. */
lwr_receive_getc = receive_getc;
lwr_receive_ungetc = receive_ungetc;
+
receive_getc = bdat_getc;
receive_ungetc = bdat_ungetc;
+ dot_ends = FALSE;
+
goto DATA_BDAT;
}
case DATA_CMD:
HAD(SCH_DATA);
+ dot_ends = TRUE;
DATA_BDAT: /* Common code for DATA and BDAT */
if (!discarded && recipients_count <= 0)