1 files changed, 3 insertions, 0 deletions
diff --git a/lib/ftp.c b/lib/ftp.c
index 08d18ca74..0b9c9b732 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -2743,6 +2743,9 @@ static CURLcode ftp_statemachine(struct Curl_easy *data,
     case FTP_AUTH:
       /* we have gotten the response to a previous AUTH command */
 
+      if(pp->cache_size)
+        return CURLE_WEIRD_SERVER_REPLY; /* Forbid pipelining in response. */
+
       /* RFC2228 (page 5) says:
        *
        * If the server is willing to accept the named security mechanism,