Fixed bug #75535

The sizeof()s for Content-Length and Transfer-Encoding were missing
the trailing ":". Apart from being generally wrong, this no longer
verified that the header actually contains a colon, leading to the
null http_header_value being used.

Additionally, in the interest of being defensive, also make sure
that http_header_value is non-null by setting it to the end of
the header line (effectively an empty string) if there is no colon.
If the following conditions are correct, this value is not going
to be used though.

2 files changed, 37 insertions, 2 deletions

diff --git a/ext/standard/http_fopen_wrapper.c b/ext/standard/http_fopen_wrapper.c
index 1822566a21..e60ac225c9 100644
--- a/ext/standard/http_fopen_wrapper.c
+++ b/ext/standard/http_fopen_wrapper.c
@@ -796,6 +796,10 @@ finish:
 						&& (*http_header_value == ' ' || *http_header_value == '\t')) {
 					http_header_value++;
 				}
+			} else {
+				/* There is no colon. Set the value to the end of the header line, which is
+				 * effectively an empty string. */
+				http_header_value = e;
 			}
 
 			if (!strncasecmp(http_header_line, "Location:", sizeof("Location:")-1)) {
@@ -812,11 +816,11 @@ finish:
 				strlcpy(location, http_header_value, sizeof(location));
 			} else if (!strncasecmp(http_header_line, "Content-Type:", sizeof("Content-Type:")-1)) {
 				php_stream_notify_info(context, PHP_STREAM_NOTIFY_MIME_TYPE_IS, http_header_value, 0);
-			} else if (!strncasecmp(http_header_line, "Content-Length:", sizeof("Content-Length")-1)) {
+			} else if (!strncasecmp(http_header_line, "Content-Length:", sizeof("Content-Length:")-1)) {
 				file_size = atoi(http_header_value);
 				php_stream_notify_file_size(context, file_size, http_header_line, 0);
 			} else if (
-				!strncasecmp(http_header_line, "Transfer-Encoding:", sizeof("Transfer-Encoding")-1)
+				!strncasecmp(http_header_line, "Transfer-Encoding:", sizeof("Transfer-Encoding:")-1)
 				&& !strncasecmp(http_header_value, "Chunked", sizeof("Chunked")-1)
 			) {
 
diff --git a/ext/standard/tests/http/bug75535.phpt b/ext/standard/tests/http/bug75535.phpt
new file mode 100644
index 0000000000..9bf298cc06
--- /dev/null
+++ b/ext/standard/tests/http/bug75535.phpt
@@ -0,0 +1,31 @@
+--TEST--
+Bug #75535: Inappropriately parsing HTTP response leads to PHP segment fault
+--SKIPIF--
+<?php require 'server.inc'; http_server_skipif('tcp://127.0.0.1:22351'); ?>
+--INI--
+allow_url_fopen=1
+--FILE--
+<?php
+require 'server.inc';
+
+$responses = array(
+	"data://text/plain,HTTP/1.0 200 Ok\r\nContent-Length\r\n",
+);
+
+$pid = http_server("tcp://127.0.0.1:22351", $responses, $output);
+
+var_dump(file_get_contents('http://127.0.0.1:22351/'));
+var_dump($http_response_header);
+
+http_server_kill($pid);
+?>
+==DONE==
+--EXPECT--
+string(0) ""
+array(2) {
+  [0]=>
+  string(15) "HTTP/1.0 200 Ok"
+  [1]=>
+  string(14) "Content-Length"
+}
+==DONE==