From 53cbea22310f1509e98f5537ef3a83c6e600629f Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Thu, 25 Sep 2014 13:44:24 +0200 Subject: file: reject paths using embedded %00 Mostly because we use C strings and they end at a binary zero so we know we can't open a file name using an embedded binary zero. Reported-by: research@g0blin.co.uk --- lib/file.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'lib/file.c') diff --git a/lib/file.c b/lib/file.c index 73df42e02..230f1c20d 100644 --- a/lib/file.c +++ b/lib/file.c @@ -196,8 +196,9 @@ static CURLcode file_connect(struct connectdata *conn, bool *done) int i; char *actual_path; #endif + int real_path_len; - real_path = curl_easy_unescape(data, data->state.path, 0, NULL); + real_path = curl_easy_unescape(data, data->state.path, 0, &real_path_len); if(!real_path) return CURLE_OUT_OF_MEMORY; @@ -222,16 +223,23 @@ static CURLcode file_connect(struct connectdata *conn, bool *done) (actual_path[2] == ':' || actual_path[2] == '|')) { actual_path[2] = ':'; actual_path++; + real_path_len--; } /* change path separators from '/' to '\\' for DOS, Windows and OS/2 */ - for(i=0; actual_path[i] != '\0'; ++i) + for(i=0; i < real_path_len; ++i) if(actual_path[i] == '/') actual_path[i] = '\\'; + else if(!actual_path[i]) /* binary zero */ + return CURLE_URL_MALFORMAT; fd = open_readonly(actual_path, O_RDONLY|O_BINARY); file->path = actual_path; #else + if(memchr(real_path, 0, real_path_len)) + /* binary zeroes indicate foul play */ + return CURLE_URL_MALFORMAT; + fd = open_readonly(real_path, O_RDONLY); file->path = real_path; #endif -- cgit v1.2.3