diff --git a/system/core/Model.php b/system/core/Model.php
index b2bbbd4d484..5ca24e0a46f 100644
--- a/system/core/Model.php
+++ b/system/core/Model.php
@@ -47,6 +47,7 @@
  * @author		EllisLab Dev Team
  * @link		https://codeigniter.com/userguide3/libraries/config.html
  */
+#[AllowDynamicProperties]
 class CI_Model {
 
 	/**
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index e91612d84af..661324c0909 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -533,6 +533,10 @@ public function from($from)
 	 */
 	public function join($table, $cond, $type = '', $escape = NULL)
 	{
+		$type = (string) $type;
+		$cond = (string) $cond;
+		$table = (string) $table;
+
 		if ($type !== '')
 		{
 			$type = strtoupper(trim($type));
@@ -1208,6 +1212,9 @@ public function or_having($key, $value = NULL, $escape = NULL)
 	 */
 	public function order_by($orderby, $direction = '', $escape = NULL)
 	{
+		$orderby = (string) $orderby;
+		$direction = (string) $direction;
+
 		$direction = strtoupper(trim($direction));
 
 		if ($direction === 'RANDOM')
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index 8c4f94d18fe..65950552f2b 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -137,33 +137,39 @@ public function field_data()
 	private static function _get_field_type($type)
 	{
 		static $map;
-		isset($map) OR $map = array(
-			MYSQLI_TYPE_DECIMAL     => 'decimal',
-			MYSQLI_TYPE_BIT         => 'bit',
-			MYSQLI_TYPE_TINY        => 'tinyint',
-			MYSQLI_TYPE_SHORT       => 'smallint',
-			MYSQLI_TYPE_INT24       => 'mediumint',
-			MYSQLI_TYPE_LONG        => 'int',
-			MYSQLI_TYPE_LONGLONG    => 'bigint',
-			MYSQLI_TYPE_FLOAT       => 'float',
-			MYSQLI_TYPE_DOUBLE      => 'double',
-			MYSQLI_TYPE_TIMESTAMP   => 'timestamp',
-			MYSQLI_TYPE_DATE        => 'date',
-			MYSQLI_TYPE_TIME        => 'time',
-			MYSQLI_TYPE_DATETIME    => 'datetime',
-			MYSQLI_TYPE_YEAR        => 'year',
-			MYSQLI_TYPE_NEWDATE     => 'date',
-			MYSQLI_TYPE_INTERVAL    => 'interval',
-			MYSQLI_TYPE_ENUM        => 'enum',
-			MYSQLI_TYPE_SET         => 'set',
-			MYSQLI_TYPE_TINY_BLOB   => 'tinyblob',
-			MYSQLI_TYPE_MEDIUM_BLOB => 'mediumblob',
-			MYSQLI_TYPE_BLOB        => 'blob',
-			MYSQLI_TYPE_LONG_BLOB   => 'longblob',
-			MYSQLI_TYPE_STRING      => 'char',
-			MYSQLI_TYPE_VAR_STRING  => 'varchar',
-			MYSQLI_TYPE_GEOMETRY    => 'geometry'
-		);
+
+		if (!isset($map)) {
+			$map = array(
+				MYSQLI_TYPE_DECIMAL     => 'decimal',
+				MYSQLI_TYPE_BIT         => 'bit',
+				MYSQLI_TYPE_TINY        => 'tinyint',
+				MYSQLI_TYPE_SHORT       => 'smallint',
+				MYSQLI_TYPE_INT24       => 'mediumint',
+				MYSQLI_TYPE_LONG        => 'int',
+				MYSQLI_TYPE_LONGLONG    => 'bigint',
+				MYSQLI_TYPE_FLOAT       => 'float',
+				MYSQLI_TYPE_DOUBLE      => 'double',
+				MYSQLI_TYPE_TIMESTAMP   => 'timestamp',
+				MYSQLI_TYPE_DATE        => 'date',
+				MYSQLI_TYPE_TIME        => 'time',
+				MYSQLI_TYPE_DATETIME    => 'datetime',
+				MYSQLI_TYPE_YEAR        => 'year',
+				MYSQLI_TYPE_NEWDATE     => 'date',
+				MYSQLI_TYPE_ENUM        => 'enum',
+				MYSQLI_TYPE_SET         => 'set',
+				MYSQLI_TYPE_TINY_BLOB   => 'tinyblob',
+				MYSQLI_TYPE_MEDIUM_BLOB => 'mediumblob',
+				MYSQLI_TYPE_BLOB        => 'blob',
+				MYSQLI_TYPE_LONG_BLOB   => 'longblob',
+				MYSQLI_TYPE_STRING      => 'char',
+				MYSQLI_TYPE_VAR_STRING  => 'varchar',
+				MYSQLI_TYPE_GEOMETRY    => 'geometry'
+			);
+
+			if (defined('MYSQLI_TYPE_INTERVAL')) {
+				$map[constant('MYSQLI_TYPE_INTERVAL')] = 'interval';
+			}
+		}
 
 		return isset($map[$type]) ? $map[$type] : $type;
 	}
diff --git a/system/libraries/Encryption.php b/system/libraries/Encryption.php
index 54d1aa99e49..80154fbb456 100644
--- a/system/libraries/Encryption.php
+++ b/system/libraries/Encryption.php
@@ -475,6 +475,8 @@ protected function _openssl_encrypt($data, $params)
 			return FALSE;
 		}
 
+		$data = (string) $data;
+
 		$iv = ($iv_size = openssl_cipher_iv_length($params['handle']))
 			? $this->create_key($iv_size)
 			: '';
@@ -626,6 +628,13 @@ protected function _mcrypt_decrypt($data, $params)
 	 */
 	protected function _openssl_decrypt($data, $params)
 	{
+		if (empty($params['handle']))
+		{
+			return FALSE;
+		}
+
+		$data = (string) $data;
+
 		if ($iv_size = openssl_cipher_iv_length($params['handle']))
 		{
 			$iv = self::substr($data, 0, $iv_size);
@@ -636,15 +645,13 @@ protected function _openssl_decrypt($data, $params)
 			$iv = '';
 		}
 
-		return empty($params['handle'])
-			? FALSE
-			: openssl_decrypt(
-				$data,
-				$params['handle'],
-				$params['key'],
-				1, // DO NOT TOUCH!
-				$iv
-			);
+		return openssl_decrypt(
+			$data,
+			$params['handle'],
+			$params['key'],
+			1, // DO NOT TOUCH!
+			$iv
+		);
 	}
 
 	// --------------------------------------------------------------------