CVE-2017-16510 (PHP, published 2017-11-02T16:29Z)
Description: value: WordPress before 4.8.3 is affected by an issue where $wpdb->prepare() can create unexpected and unsafe queries leading to potential SQL injection (SQLi) in plugins and themes, as demonstrated by a "double prepare" approach, a different vulnerability than CVE-2017-14723.
Severity: HIGH (CVSS v3 base score: 9.8)
Weakness: CWE-89 \u2014 Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.
Repository: https://github.com/WordPress/WordPress
Files changed:
wp-includes/formatting.php
wp-includes/meta.php
wp-includes/post.php
wp-includes/version.php
wp-includes/wp-db.php
Commit message: Database: Restore numbered placeholders in `wpdb::prepare()`.

[41496] removed support for numbered placeholders in queries send through `wpdb::prepare()`, which, despite being undocumented, were quite commonly used.

This change restores support for numbered placeholders (as well as a subset of placeholder formatting), while also adding extra checks to ensure the correct number of arguments are being passed to `wpdb::prepare()`, given the number of placeholders.

See #41925.


Built from https://develop.svn.wordpress.org/trunk@42056


git-svn-id: http://core.svn.wordpress.org/trunk@41885 1a063a9b-81f0-0310-95a4-ce76da25c4cd


Vulnerable code:
		$value_clause = '';
			$value_clause = $wpdb->prepare( " AND meta_value = %s", $meta_value );

		$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s $value_clause", $meta_key ) );
	$parts = esc_sql( $parts );
	$in_string = "'" . implode( "','", $parts ) . "'";
$wp_version = '4.9-RC1-42050';
				return mysqli_real_escape_string( $this->dbh, $string );
				return mysql_real_escape_string( $string, $this->dbh );
		}

		$class = get_class( $this );
		if ( function_exists( '__' ) ) {
			/* translators: %s: database access abstraction class, usually wpdb or a class extending wpdb */
			_doing_it_wrong( $class, sprintf( __( '%s must set a database connection for use with escaping.' ), $class ), '3.6.0' );
			_doing_it_wrong( $class, sprintf( '%s must set a database connection for use with escaping.', $class ), '3.6.0' );
		return addslashes( $string );
	 * This method DOES NOT support sign, padding, alignment, width or precision specifiers.
	 * This method DOES NOT support argument numbering or swapping.
	 *
	 * Arguments may be passed as individual arguments to the method, or as a single array containing all arguments. A combination 
		if ( is_null( $query ) )
		// If args were passed as an array (as in vsprintf), move them up
		$query = str_replace( "'%s'", '%s', $query ); // in case someone mistakenly already singlequoted it
		$query = str_replace( '"%s"', '%s', $query ); // doublequote unquoting
		$query = preg_replace( '|(?<!%)%f|' , '%F', $query ); // Force floats to be locale unaware
		$query = preg_replace( '|(?<!%)%s|', "'%s'", $query ); // quote the strings, avoiding escaped strings like %%s
		$query = preg_replace( '/%(?:%|$|([^dsF]))/', '%%\\1', $query ); // escape any unescaped percents
		// Count the number of valid placeholders in the query
		$placeholders = preg_match_all( '/(^|[^%]|(%%)+)%[sdF]/', $query, $matches );
		if ( count ( $args ) !== $placeholders ) {
			wp_load_translations_early();
			_doing_it_wrong( 'wpdb::prepare',
				/* translators: 1: number of placeholders, 2: number of arguments passed */
				sprintf( __( 'The query does not contain the correct number of placeholders (%1$d) for the number of arguments passed (%2$d).' ),
					$placeholders,
					count( $args ) ),
				'4.9.0'
			);
		return @vsprintf( $query, $args );
		

Fixed code:
 * NOTE: Since 4.8.3, '%' characters will be replaced with a placeholder string,
 * this prevents certain SQLi attacks from taking place. This change in behaviour
 * may cause issues for code that expects the return value of esc_sql() to be useable
 * for other purposes.
 *
			$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s AND meta_value = %s", $meta_key, $meta_value ) );
		} else {
			$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s", $meta_key ) );
	$escaped_parts = esc_sql( $parts );
	$in_string = "'" . implode( "','", $escaped_parts ) . "'";
$wp_version = '4.9-RC1-42056';
				$escaped = mysqli_real_escape_string( $this->dbh, $string );
				$escaped = mysql_real_escape_string( $string, $this->dbh );
			$class = get_class( $this );
			if ( function_exists( '__' ) ) {
				/* translators: %s: database access abstraction class, usually wpdb or a class extending wpdb */
				_doing_it_wrong( $class, sprintf( __( '%s must set a database connection for use with escaping.' ), $class ), '3.6.0' );
			} else {
				_doing_it_wrong( $class, sprintf( '%s must set a database connection for use with escaping.', $class ), '3.6.0' );
			}
			$escaped = addslashes( $string );

		return $this->add_placeholder_escape( $escaped );
	 * For compatibility with old behavior, numbered or formatted string placeholders (eg, %1$s, %5s) will not have quotes
	 * added by this function, so should be passed with appropriate quotes around them for your usage.
	 *
	 * Arguments may be passed as individual arguments to the method, or as a single array containing all arguments. A combination
		if ( is_null( $query ) ) {
		}
		// If args were passed as an array (as in vsprintf), move them up.
		$passed_as_array = false;
			$passed_as_array = true;
		/*
		 * Specify the formatting allowed in a placeholder. The following are allowed:
		 *
		 * - Sign specifier. eg, $+d
		 * - Numbered placeholders. eg, %1$s
		 * - Padding specifier, including custom padding characters. eg, %05s, %'#5s
		 * - Alignment specifier. eg, %05-s
		 * - Precision specifier. eg, %.2f
		 */
		$allowed_format = '(?:[1-9][0-9]*[$])?[-+0-9]*(?: |0|\'.)?[-+0-9]*(?:\.[0-9]+)?';

		/*
		 * If a %s placeholder already has quotes around it, removing the existing quotes and re-inserting them
		 * ensures the quotes are consistent.
		 *
		 * For backwards compatibility, this is only applied to %s, and not to placeholders like %1$s, which are frequently
		 * used in the middle of longer strings, or as table name placeholders.
		 */
		$query = str_replace( "'%s'", '%s', $query ); // Strip any existing single quotes.
		$query = str_replace( '"%s"', '%s', $query ); // Strip any existing double quotes.
		$query = preg_replace( '/(?<!%)%s/', "'%s'", $query ); // Quote the strings, avoiding escaped strings like %%s.

		$query = preg_replace( "/(?<!%)(%($allowed_format)?f)/" , '%\\2F', $query ); // Force floats to be locale unaware.
		$query = preg_replace( "/%(?:%|$|(?!($allowed_format)?[sdF]))/", '%%\\1', $query ); // Escape any unescaped percents.
		// Count the number of valid placeholders in the query.
		$placeholders = preg_match_all( "/(^|[^%]|(%%)+)%($allowed_format)?[sdF]/", $query, $matches );

		if ( count( $args ) !== $placeholders ) {
			if ( 1 === $placeholders && $passed_as_array ) {
				// If the passed query only expected one argument, but the wrong number of arguments were sent as an array, bail.
				wp_load_translations_early();
				_doing_it_wrong( 'wpdb::prepare', __( 'The query only expected one placeholder, but an array of multiple placeholders was sent.' ), '4.9.0' );

				return;
			} else {
				/*
				 * If we don't have the right number of placeholders, but they were passed as individual arguments,
				 * or we were expecting multiple arguments in an array, throw a warning.
				 */
				wp_load_translations_early();
				_doing_it_wrong( 'wpdb::prepare',
					/* translators: 1: number of placeholders, 2: number of arguments passed */
					sprintf( __( 'The query does not contain the correct number of placeholders (%1$d) for the number of arguments passed (%2$d).' ),
						$placeholders,
						count( $args ) ),
					'4.8.3'
				);
			}
		$query = @vsprintf( $query, $args );

		return $this->add_placeholder_escape( $query );
	/**
	 * Generates and returns a placeholder escape string for use in queries returned by ::prepare().
	 *
	 * @since 4.8.3
	 *
	 * @return string String to escape placeholders.
	 */
	public function placeholder_escape() {
		static $placeholder;

		if ( ! $placeholder ) {
			// If ext/hash is not present, compat.php's hash_hmac() does not support sha256.
			$algo = function_exists( 'hash' ) ? 'sha256' : 'sha1';
			// Old WP installs may not have AUTH_SALT defined.
			$salt = defined( 'AUTH_SALT' ) ? AUTH_SALT : rand();

			$placeholder = '{' . hash_hmac( $algo, uniqid( $salt, true ), $salt ) . '}';
		}

		/*
		 * Add the filter to remove the placeholder escaper. Uses priority 0, so that anything
		 * else attached to this filter will recieve the query with the placeholder string removed.
		 */
		if ( ! has_filter( 'query', array( $this, 'remove_placeholder_escape' ) ) ) {
			add_filter( 'query', array( $this, 'remove_placeholder_escape' ), 0 );
		}

		return $placeholder;
	}

	/**
	 * Adds a placeholder escape string, to escape anything that resembles a printf() placeholder.
	 *
	 * @since 4.8.3
	 *
	 * @param string $query The query to escape.
	 * @return string The query with the placeholder escape string inserted where necessary.
	 */
	public function add_placeholder_escape( $query ) {
		/*
		 * To prevent returning anything that even vaguely resembles a placeholder,
		 * we clobber every % we can find.
		 */
		return str_replace( '%', $this->placeholder_escape(), $query );
	}

	/**
	 * Removes the placeholder escape strings from a query.
	 *
	 * @since 4.8.3
	 *
	 * @param string $query The query from which the placeholder will be removed.
	 * @return string The query with the placeholder removed.
	 */
	public function remove_placeholder_escape( $query ) {
		return str_replace( $this->placeholder_escape(), '%', $query );
	}