diff --git a/src/config.m4 b/src/config.m4
index a2301fd1..ddbd7a16 100644
--- a/src/config.m4
+++ b/src/config.m4
@@ -7,7 +7,7 @@ sources="$sources sp_disabled_functions.c sp_execute.c sp_upload_validation.c"
 sources="$sources sp_cookie_encryption.c sp_network_utils.c tweetnacl.c"
 sources="$sources sp_config_keywords.c sp_var_parser.c sp_var_value.c sp_tree.c"
 sources="$sources sp_pcre_compat.c sp_crypt.c sp_session.c sp_sloppy.c sp_wrapper.c"
-sources="$sources sp_ini.c sp_php_compat.c sp_config_scanner.c"
+sources="$sources sp_ini.c sp_php_compat.c sp_config_scanner.c sp_ifilter.c"
 
 PHP_ARG_ENABLE(snuffleupagus, whether to enable snuffleupagus support,
 [  --enable-snuffleupagus           Enable snuffleupagus support])
diff --git a/src/php_snuffleupagus.h b/src/php_snuffleupagus.h
index 0c7dc4b8..bcb613ce 100644
--- a/src/php_snuffleupagus.h
+++ b/src/php_snuffleupagus.h
@@ -88,6 +88,7 @@ typedef void (*zif_handler)(INTERNAL_FUNCTION_PARAMETERS);
 #include "sp_sloppy.h"
 #include "sp_wrapper.h"
 #include "sp_ini.h"
+#include "sp_ifilter.h"
 
 extern zend_module_entry snuffleupagus_module_entry;
 #define phpext_snuffleupagus_ptr &snuffleupagus_module_entry
diff --git a/src/snuffleupagus.c b/src/snuffleupagus.c
index d2f81ffd..50711f01 100644
--- a/src/snuffleupagus.c
+++ b/src/snuffleupagus.c
@@ -383,6 +383,8 @@ static PHP_INI_MH(OnUpdateConfiguration) {
     sp_hook_ini();
   }
 
+  sp_hook_register_server_variables();
+
   if (true == SNUFFLEUPAGUS_G(config).config_global_strict->enable) {
     if (!zend_get_extension(PHP_SNUFFLEUPAGUS_EXTNAME)) {
       zend_extension_entry.startup = NULL;
diff --git a/src/sp_config.h b/src/sp_config.h
index ccf23184..af9b905c 100644
--- a/src/sp_config.h
+++ b/src/sp_config.h
@@ -197,6 +197,8 @@ typedef struct {
   bool hook_execute;
   char log_media;
   u_long max_execution_depth;
+  bool server_encode;
+  bool server_strip;
 
   HashTable *config_disabled_functions;
   HashTable *config_disabled_functions_hooked;
@@ -288,6 +290,8 @@ typedef struct {
 #define SP_TOKEN_ENV_VAR "cookie_env_var"
 #define SP_TOKEN_LOG_MEDIA "log_media"
 #define SP_TOKEN_MAX_EXECUTION_DEPTH "max_execution_depth"
+#define SP_TOKEN_SERVER_ENCODE "server_encode"
+#define SP_TOKEN_SERVER_STRIP "server_strip"
 
 // upload_validator
 #define SP_TOKEN_UPLOAD_SCRIPT "script"
diff --git a/src/sp_config_keywords.c b/src/sp_config_keywords.c
index 632f9bd0..38b85269 100644
--- a/src/sp_config_keywords.c
+++ b/src/sp_config_keywords.c
@@ -129,6 +129,8 @@ SP_PARSE_FN(parse_global) {
       {parse_str, SP_TOKEN_ENV_VAR, &(SNUFFLEUPAGUS_G(config).config_snuffleupagus->cookies_env_var)},
       {parse_log_media, SP_TOKEN_LOG_MEDIA, &(SNUFFLEUPAGUS_G(config).log_media)},
       {parse_ulong, SP_TOKEN_MAX_EXECUTION_DEPTH, &(SNUFFLEUPAGUS_G(config).max_execution_depth)},
+      {parse_enable, SP_TOKEN_SERVER_ENCODE, &(SNUFFLEUPAGUS_G(config).server_encode)},
+      {parse_enable, SP_TOKEN_SERVER_STRIP, &(SNUFFLEUPAGUS_G(config).server_strip)},
       {0, 0, 0}};
 
   SP_PROCESS_CONFIG_KEYWORDS_ERR();
diff --git a/src/sp_ifilter.c b/src/sp_ifilter.c
new file mode 100644
index 00000000..171138f4
--- /dev/null
+++ b/src/sp_ifilter.c
@@ -0,0 +1,103 @@
+#include "php_snuffleupagus.h"
+
+static void (*orig_register_server_variables)(zval *track_vars_array) = NULL;
+
+static const unsigned char sp_hexchars[] = "0123456789ABCDEF";
+
+static const char sp_is_dangerous_char[256] = {
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+static void sp_server_strip(HashTable *svars, char *key, int keylen) {
+  zval *value = zend_hash_str_find(svars, key, keylen);
+  if (!value || Z_TYPE_P(value) != IS_STRING) { return; }
+
+  zend_string *tmp_zstr = Z_STR_P(value);
+  char *tmp = ZSTR_VAL(tmp_zstr);
+  char *tmpend = tmp + ZSTR_LEN(tmp_zstr);
+
+  for (char *p = tmp; p < tmpend; p++) {
+    if (sp_is_dangerous_char[(int)*p]) {
+      *p = '_';
+    }
+  }
+}
+
+static void sp_server_encode(HashTable *svars, char *key, int keylen) {
+  zval *value = zend_hash_str_find(svars, key, keylen);
+  if (!value || Z_TYPE_P(value) != IS_STRING) { return; }
+  
+  zend_string *tmp_zstr = Z_STR_P(value);
+  char *tmp = ZSTR_VAL(tmp_zstr);
+  char *tmpend = tmp + ZSTR_LEN(tmp_zstr);
+  int extra = 0;
+  
+  for (char *p = tmp; p < tmpend; p++) {
+    extra += sp_is_dangerous_char[(int)*p] * 2;
+  }
+  if (!extra) { return; }
+
+  zend_string *new_zstr = zend_string_alloc(ZSTR_LEN(tmp_zstr) + extra, 0);
+  char *n = ZSTR_VAL(new_zstr);
+  for (char *p = tmp; p < tmpend; p++, n++) {
+    if (sp_is_dangerous_char[(int)*p]) {
+      *n++ = '%';
+      *n++ = sp_hexchars[*p >> 4];
+      *n = sp_hexchars[*p & 15];
+    } else {
+      *n = *p;
+    }
+  }
+  ZSTR_VAL(new_zstr)[ZSTR_LEN(new_zstr)] = 0;
+  Z_STR_P(value) = new_zstr;
+
+  zend_string_release_ex(tmp_zstr, 0);
+}
+
+static void sp_register_server_variables(zval *track_vars_array) {
+  orig_register_server_variables(track_vars_array);
+
+  HashTable *svars;
+  svars = Z_ARRVAL_P(track_vars_array);
+
+
+  if (SNUFFLEUPAGUS_G(config).server_encode) {
+    sp_server_encode(svars, ZEND_STRL("REQUEST_URI"));
+    sp_server_encode(svars, ZEND_STRL("QUERY_STRING"));
+  }
+
+  if (SNUFFLEUPAGUS_G(config).server_strip) {
+    sp_server_strip(svars, ZEND_STRL("PHP_SELF"));
+    sp_server_strip(svars, ZEND_STRL("HTTP_HOST"));
+    sp_server_strip(svars, ZEND_STRL("HTTP_USER_AGENT"));
+
+    // for cgi + fpm
+    sp_server_strip(svars, ZEND_STRL("PATH_INFO"));
+    sp_server_strip(svars, ZEND_STRL("PATH_TRANSLATED"));
+    sp_server_strip(svars, ZEND_STRL("ORIG_PATH_TRANSLATED"));
+    sp_server_strip(svars, ZEND_STRL("ORIG_PATH_INFO"));
+  }
+}
+
+void sp_hook_register_server_variables()
+{
+  if (sapi_module.register_server_variables) {
+    orig_register_server_variables = sapi_module.register_server_variables;
+    sapi_module.register_server_variables = sp_register_server_variables;
+  }
+}
diff --git a/src/sp_ifilter.h b/src/sp_ifilter.h
new file mode 100644
index 00000000..527c41d5
--- /dev/null
+++ b/src/sp_ifilter.h
@@ -0,0 +1,3 @@
+#pragma once
+
+void sp_hook_register_server_variables();
diff --git a/src/tests/filter/config/filter.ini b/src/tests/filter/config/filter.ini
new file mode 100644
index 00000000..5ebee614
--- /dev/null
+++ b/src/tests/filter/config/filter.ini
@@ -0,0 +1,3 @@
+sp.global.server_encode.enable();
+sp.global.server_strip.enable();
+
diff --git a/src/tests/filter/server_encode.phpt b/src/tests/filter/server_encode.phpt
new file mode 100644
index 00000000..f7cc2332
--- /dev/null
+++ b/src/tests/filter/server_encode.phpt
@@ -0,0 +1,25 @@
+--TEST--
+input filter: server_encode
+--SKIPIF--
+<?php if (!extension_loaded("snuffleupagus")) print "skip"; ?>
+--INI--
+sp.configuration_file={PWD}/config/filter.ini
+display_errors=1
+display_startup_errors=1
+error_reporting=E_ALL
+--ENV--
+return <<<EOF
+REQUEST_URI=AAA<>"'`!AAA
+EOF;
+--COOKIE--
+--GET--
+BBB<>"'`!BBB
+--POST--
+--FILE--
+<?php
+var_dump($_SERVER['REQUEST_URI']);
+var_dump($_SERVER['QUERY_STRING']);
+--EXPECT--
+string(22) "AAA%3C%3E%22%27%60!AAA"
+string(22) "BBB%3C%3E%22%27%60!BBB"
+
diff --git a/src/tests/filter/server_strip.phpt b/src/tests/filter/server_strip.phpt
new file mode 100644
index 00000000..83072b41
--- /dev/null
+++ b/src/tests/filter/server_strip.phpt
@@ -0,0 +1,21 @@
+--TEST--
+input filter: server_strip
+--SKIPIF--
+<?php if (!extension_loaded("snuffleupagus")) print "skip"; ?>
+--INI--
+sp.configuration_file={PWD}/config/filter.ini
+display_errors=1
+display_startup_errors=1
+error_reporting=E_ALL
+--ENV--
+return <<<EOF
+HTTP_USER_AGENT=Mozilla/5.0 (Windows NT 6.0; rv:29.0) <script>alert('123');</script>Gecko/20100101 Firefox/29.0
+EOF;
+--COOKIE--
+--GET--
+--POST--
+--FILE--
+<?php
+var_dump($_SERVER['HTTP_USER_AGENT']);
+--EXPECT--
+string(95) "Mozilla/5.0 (Windows NT 6.0; rv:29.0) _script_alert(_123_);_/script_Gecko/20100101 Firefox/29.0"