From ba1dbd78e5f1ed67c1b8d37ac89d90e5e330b628 Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Wed, 13 Jun 2018 12:24:40 +0200 Subject: [PATCH] smtp: use the upload buffer size for scratch buffer malloc ... not the read buffer size, as that can be set smaller and thus cause a buffer overflow! CVE-2018-0500 Reported-by: Peter Wu Bug: https://curl.haxx.se/docs/adv_2018-70a2.html --- lib/smtp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/lib/smtp.c +++ b/lib/smtp.c @@ -1563,13 +1563,14 @@ CURLcode Curl_smtp_escape_eob(struct con if(!scratch || data->set.crlf) { oldscratch = scratch; - scratch = newscratch = malloc(2 * data->set.buffer_size); + scratch = newscratch = malloc(2 * UPLOAD_BUFSIZE); if(!newscratch) { failf(data, "Failed to alloc scratch buffer!"); return CURLE_OUT_OF_MEMORY; } } + DEBUGASSERT(UPLOAD_BUFSIZE >= nread); /* Have we already sent part of the EOB? */ eob_sent = smtp->eob;