Do not decode cookie names anymore

(cherry picked from commit 95e1a41)

Author: smalyshev

NEWS

@@ -6,6 +6,8 @@ PHP                                                                        NEWS
   . Fixed bug #80048 (Bug #69100 has not been fixed for Windows). (cmb)
   . Fixed bug #80049 (Memleak when coercing integers to string via variadic
     argument). (Nikita)
+  . Fixed bug ##79699 (PHP parses encoded cookie names so malicious `__Host-` 
+    cookies can be sent). (CVE-2020-7070) (Stas)
 
 - Calendar:
   . Fixed bug #80007 (Potential type confusion in unixtojd() parameter parsing).

UPGRADING

@@ -151,6 +151,11 @@ Reflection:
   . Reflection export to string now uses `int` and `bool` instead of `integer`
     and `boolean`.
 
+SAPI:
+  . Starting with 7.3.24, incoming cookie names are not url-decoded. This was never 
+    required by the standard, outgoing cookie names aren't encoded and this leads 
+    to security issues (CVE-2020-7070).
+
 SPL:
   . If an SPL autoloader throws an exception, following autoloaders will not be
     executed. Previously all autoloaders were executed and exceptions were

main/php_variables.c

@@ -501,7 +501,9 @@ SAPI_API SAPI_TREAT_DATA_FUNC(php_default_treat_data)
 			size_t new_val_len;
 
 			*val++ = '\0';
-			php_url_decode(var, strlen(var));
+			if (arg != PARSE_COOKIE) {
+				php_url_decode(var, strlen(var));
+			}
 			val_len = php_url_decode(val, strlen(val));
 			val = estrndup(val, val_len);
 			if (sapi_module.input_filter(arg, var, &val, val_len, &new_val_len)) {
@@ -512,7 +514,9 @@ SAPI_API SAPI_TREAT_DATA_FUNC(php_default_treat_data)
 			size_t val_len;
 			size_t new_val_len;
 
-			php_url_decode(var, strlen(var));
+			if (arg != PARSE_COOKIE) {
+				php_url_decode(var, strlen(var));
+			}
 			val_len = 0;
 			val = estrndup("", val_len);
 			if (sapi_module.input_filter(arg, var, &val, val_len, &new_val_len)) {

tests/basic/022.phpt

@@ -10,7 +10,7 @@ cookie1=val1  ; cookie2=val2%20; cookie3=val 3.; cookie 4= value 4 %3B; cookie1=
 var_dump($_COOKIE);
 ?>
 --EXPECT--
-array(10) {
+array(12) {
   ["cookie1"]=>
   string(6) "val1  "
   ["cookie2"]=>
@@ -19,11 +19,15 @@ array(10) {
   string(6) "val 3."
   ["cookie_4"]=>
   string(10) " value 4 ;"
+  ["%20cookie1"]=>
+  string(6) "ignore"
+  ["+cookie1"]=>
+  string(6) "ignore"
   ["cookie__5"]=>
   string(7) "  value"
-  ["cookie_6"]=>
+  ["cookie%206"]=>
   string(3) "þæö"
-  ["cookie_7"]=>
+  ["cookie+7"]=>
   string(0) ""
   ["$cookie_8"]=>
   string(0) ""

tests/basic/023.phpt

@@ -10,9 +10,11 @@ c o o k i e=value; c o o k i e= v a l u e ;;c%20o+o k+i%20e=v;name="value","valu
 var_dump($_COOKIE);
 ?>
 --EXPECT--
-array(3) {
+array(4) {
   ["c_o_o_k_i_e"]=>
   string(5) "value"
+  ["c%20o+o_k+i%20e"]=>
+  string(1) "v"
   ["name"]=>
   string(24) ""value","value",UEhQIQ=="
   ["UEhQIQ"]=>

tests/basic/bug79699.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Cookies Security Bug
+--INI--
+max_input_vars=1000
+filter.default=unsafe_raw
+--COOKIE--
+__%48ost-evil=evil; __Host-evil=good; %66oo=baz;foo=bar
+--FILE--
+<?php
+var_dump($_COOKIE);
+?>
+--EXPECT--
+array(4) {
+  ["__%48ost-evil"]=>
+  string(4) "evil"
+  ["__Host-evil"]=>
+  string(4) "good"
+  ["%66oo"]=>
+  string(3) "baz"
+  ["foo"]=>
+  string(3) "bar"
+}