diff options
| author | Daniel Gustafsson <daniel@yesql.se> | 2019-01-19 00:42:47 +0100 |
|---|---|---|
| committer | Daniel Stenberg <daniel@haxx.se> | 2019-02-04 08:22:32 +0100 |
| commit | 39df4073e5413fcdbb5a38da0c1ce6f1c0ceb484 (patch) | |
| tree | d27fd08698a3365ab1d4ee8dc8dd050fcc8d7c2f | |
| parent | 50c9484278c63b958655a717844f0721263939cc (diff) | |
smtp: avoid risk of buffer overflow in strtol
If the incoming len 5, but the buffer does not have a termination
after 5 bytes, the strtol() call may keep reading through the line
buffer until is exceeds its boundary. Fix by ensuring that we are
using a bounded read with a temporary buffer on the stack.
Bug: https://curl.haxx.se/docs/CVE-2019-3823.html
Reported-by: Brian Carpenter (Geeknik Labs)
CVE-2019-3823
| -rw-r--r-- | lib/smtp.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/smtp.c b/lib/smtp.c index 84fc68e41..d55647b12 100644 --- a/lib/smtp.c +++ b/lib/smtp.c @@ -5,7 +5,7 @@ * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * - * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al. + * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms @@ -207,8 +207,12 @@ static bool smtp_endofresp(struct connectdata *conn, char *line, size_t len, Section 4. Examples of RFC-4954 but some e-mail servers ignore this and only send the response code instead as per Section 4.2. */ if(line[3] == ' ' || len == 5) { + char tmpline[6]; + result = TRUE; - *resp = curlx_sltosi(strtol(line, NULL, 10)); + memset(tmpline, '\0', sizeof(tmpline)); + memcpy(tmpline, line, (len == 5 ? 5 : 3)); + *resp = curlx_sltosi(strtol(tmpline, NULL, 10)); /* Make sure real server never sends internal value */ if(*resp == 1) |