Database: Revert [53575].

When using `'%%%s%%'` pattern with `$wpdb->prepare()`, it works on 6.0.3 but does not on 6.1-RC. Why? The inserted value is wrapped in quotes on 6.1-RC5 whereas it is not on <= 6.0.3.

With 6.1 final release tomorrow, more time is needed to further investigate and test. Reverting this changeset to restore the previous behavior.

This commit also adds a dataset for testing the `'%%%s%%'` pattern.

Props SergeyBiryukov, hellofromTonya, bernhard-reiter, desrosj, davidbaumwald, jorbin.

Fixes #56933.
See #52506.

git-svn-id: https://develop.svn.wordpress.org/trunk@54733 602fd350-edb4-49c9-b593-d223f7449a82
This commit is contained in:
Tonya Mork
2022-10-31 20:38:20 +00:00
parent 2b638bea23
commit 7e2a0a9572
2 changed files with 47 additions and 337 deletions
+36 -215
View File
@@ -654,41 +654,6 @@ class wpdb {
'ANSI',
);
/**
* Backward compatibility, where wpdb::prepare() has not quoted formatted/argnum placeholders.
*
* Historically this could be used for table/field names, or for some string formatting, e.g.
*
* $wpdb->prepare( 'WHERE `%1s` = "%1s something %1s" OR %1$s = "%-10s"', 'field_1', 'a', 'b', 'c' );
*
* But it's risky, e.g. forgetting to add quotes, resulting in SQL Injection vulnerabilities:
*
* $wpdb->prepare( 'WHERE (id = %1s) OR (id = %2$s)', $_GET['id'], $_GET['id'] ); // ?id=id
*
* This feature is preserved while plugin authors update their code to use safer approaches:
*
* $wpdb->prepare( 'WHERE %1s = %s', $_GET['key'], $_GET['value'] );
* $wpdb->prepare( 'WHERE %i = %s', $_GET['key'], $_GET['value'] );
*
* While changing to false will be fine for queries not using formatted/argnum placeholders,
* any remaining cases are most likely going to result in SQL errors (good, in a way):
*
* $wpdb->prepare( 'WHERE %1s = "%-10s"', 'my_field', 'my_value' );
* true = WHERE my_field = "my_value "
* false = WHERE 'my_field' = "'my_value '"
*
* But there may be some queries that result in an SQL Injection vulnerability:
*
* $wpdb->prepare( 'WHERE id = %1s', $_GET['id'] ); // ?id=id
*
* So there may need to be a `_doing_it_wrong()` phase, after we know everyone can use
* identifier placeholders (%i), but before this feature is disabled or removed.
*
* @since 6.1.0
* @var bool
*/
private $allow_unsafe_unquoted_parameters = true;
/**
* Whether to use mysqli over mysql. Default false.
*
@@ -1397,37 +1362,6 @@ class wpdb {
}
}
/**
* Escapes an identifier for a MySQL database, e.g. table/field names.
*
* @since 6.1.0
*
* @param string $identifier Identifier to escape.
* @return string Escaped identifier.
*/
public function escape_identifier( $identifier ) {
return '`' . $this->_escape_identifier_value( $identifier ) . '`';
}
/**
* Escapes an identifier value without adding the surrounding quotes.
*
* - Permitted characters in quoted identifiers include the full Unicode
* Basic Multilingual Plane (BMP), except U+0000.
* - To quote the identifier itself, you need to double the character, e.g. `a``b`.
*
* @since 6.1.0
* @access private
*
* @link https://dev.mysql.com/doc/refman/8.0/en/identifiers.html
*
* @param string $identifier Identifier to escape.
* @return string Escaped identifier.
*/
private function _escape_identifier_value( $identifier ) {
return str_replace( '`', '``', $identifier );
}
/**
* Prepares a SQL query for safe execution.
*
@@ -1436,7 +1370,6 @@ class wpdb {
* - %d (integer)
* - %f (float)
* - %s (string)
* - %i (identifier, e.g. table/field names)
*
* All placeholders MUST be left unquoted in the query string. A corresponding argument
* MUST be passed for each placeholder.
@@ -1469,10 +1402,6 @@ class wpdb {
* @since 5.3.0 Formalized the existing and already documented `...$args` parameter
* by updating the function signature. The second parameter was changed
* from `$args` to `...$args`.
* @since 6.1.0 Added `%i` for identifiers, e.g. table or field names.
* Check support via `wpdb::has_cap( 'identifier_placeholders' )`.
* This preserves compatibility with sprintf(), as the C version uses
* `%d` and `$i` as a signed integer, whereas PHP only supports `%d`.
*
* @link https://www.php.net/sprintf Description of syntax.
*
@@ -1504,6 +1433,28 @@ class wpdb {
);
}
// If args were passed as an array (as in vsprintf), move them up.
$passed_as_array = false;
if ( isset( $args[0] ) && is_array( $args[0] ) && 1 === count( $args ) ) {
$passed_as_array = true;
$args = $args[0];
}
foreach ( $args as $arg ) {
if ( ! is_scalar( $arg ) && ! is_null( $arg ) ) {
wp_load_translations_early();
_doing_it_wrong(
'wpdb::prepare',
sprintf(
/* translators: %s: Value type. */
__( 'Unsupported value type (%s).' ),
gettype( $arg )
),
'4.8.2'
);
}
}
/*
* Specify the formatting allowed in a placeholder. The following are allowed:
*
@@ -1524,106 +1475,20 @@ class wpdb {
*/
$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.
// Escape any unescaped percents (i.e. anything unrecognised).
$query = preg_replace( "/%(?:%|$|(?!($allowed_format)?[sdfFi]))/", '%%\\1', $query );
$query = preg_replace( "/(?<!%)(%($allowed_format)?f)/", '%\\2F', $query ); // Force floats to be locale-unaware.
// Extract placeholders from the query.
$split_query = preg_split( "/(^|[^%]|(?:%%)+)(%(?:$allowed_format)?[sdfFi])/", $query, -1, PREG_SPLIT_DELIM_CAPTURE );
$query = preg_replace( "/%(?:%|$|(?!($allowed_format)?[sdF]))/", '%%\\1', $query ); // Escape any unescaped percents.
$split_query_count = count( $split_query );
/*
* Split always returns with 1 value before the first placeholder (even with $query = "%s"),
* then 3 additional values per placeholder.
*/
$placeholder_count = ( ( $split_query_count - 1 ) / 3 );
// If args were passed as an array, as in vsprintf(), move them up.
$passed_as_array = ( isset( $args[0] ) && is_array( $args[0] ) && 1 === count( $args ) );
if ( $passed_as_array ) {
$args = $args[0];
}
$new_query = '';
$key = 2; // Keys 0 and 1 in $split_query contain values before the first placeholder.
$arg_id = 0;
$arg_identifiers = array();
$arg_strings = array();
while ( $key < $split_query_count ) {
$placeholder = $split_query[ $key ];
$format = substr( $placeholder, 1, -1 );
$type = substr( $placeholder, -1 );
if ( 'f' === $type ) { // Force floats to be locale-unaware.
$type = 'F';
$placeholder = '%' . $format . $type;
}
if ( 'i' === $type ) {
$placeholder = '`%' . $format . 's`';
// Using a simple strpos() due to previous checking (e.g. $allowed_format).
$argnum_pos = strpos( $format, '$' );
if ( false !== $argnum_pos ) {
// sprintf() argnum starts at 1, $arg_id from 0.
$arg_identifiers[] = ( intval( substr( $format, 0, $argnum_pos ) ) - 1 );
} else {
$arg_identifiers[] = $arg_id;
}
} elseif ( 'd' !== $type && 'F' !== $type ) {
/*
* i.e. ( 's' === $type ), where 'd' and 'F' keeps $placeholder unchanged,
* and we ensure string escaping is used as a safe default (e.g. even if 'x').
*/
$argnum_pos = strpos( $format, '$' );
if ( false !== $argnum_pos ) {
$arg_strings[] = ( intval( substr( $format, 0, $argnum_pos ) ) - 1 );
}
// Unquoted strings for backward compatibility (dangerous).
if ( true !== $this->allow_unsafe_unquoted_parameters || '' === $format ) {
$placeholder = "'%" . $format . "s'";
}
}
// Glue (-2), any leading characters (-1), then the new $placeholder.
$new_query .= $split_query[ $key - 2 ] . $split_query[ $key - 1 ] . $placeholder;
$key += 3;
$arg_id++;
}
// Replace $query; and add remaining $query characters, or index 0 if there were no placeholders.
$query = $new_query . $split_query[ $key - 2 ];
$dual_use = array_intersect( $arg_identifiers, $arg_strings );
if ( count( $dual_use ) ) {
wp_load_translations_early();
_doing_it_wrong(
'wpdb::prepare',
sprintf(
/* translators: %s: A comma-separated list of arguments found to be a problem. */
__( 'Arguments (%s) cannot be used for both String and Identifier escaping.' ),
implode( ', ', $dual_use )
),
'6.1.0'
);
return;
}
// Count the number of valid placeholders in the query.
$placeholders = preg_match_all( "/(^|[^%]|(%%)+)%($allowed_format)?[sdF]/", $query, $matches );
$args_count = count( $args );
if ( $args_count !== $placeholder_count ) {
if ( 1 === $placeholder_count && $passed_as_array ) {
/*
* If the passed query only expected one argument,
* but the wrong number of arguments was sent as an array, bail.
*/
if ( $args_count !== $placeholders ) {
if ( 1 === $placeholders && $passed_as_array ) {
// If the passed query only expected one argument, but the wrong number of arguments were sent as an array, bail.
wp_load_translations_early();
_doing_it_wrong(
'wpdb::prepare',
@@ -1644,7 +1509,7 @@ class wpdb {
sprintf(
/* translators: 1: Number of placeholders, 2: Number of arguments passed. */
__( 'The query does not contain the correct number of placeholders (%1$d) for the number of arguments passed (%2$d).' ),
$placeholder_count,
$placeholders,
$args_count
),
'4.8.3'
@@ -1654,17 +1519,8 @@ class wpdb {
* If we don't have enough arguments to match the placeholders,
* return an empty string to avoid a fatal error on PHP 8.
*/
if ( $args_count < $placeholder_count ) {
$max_numbered_placeholder = 0;
for ( $i = 2, $l = $split_query_count; $i < $l; $i += 3 ) {
// Assume a leading number is for a numbered placeholder, e.g. '%3$s'.
$argnum = intval( substr( $split_query[ $i ], 1 ) );
if ( $max_numbered_placeholder < $argnum ) {
$max_numbered_placeholder = $argnum;
}
}
if ( $args_count < $placeholders ) {
$max_numbered_placeholder = ! empty( $matches[3] ) ? max( array_map( 'intval', $matches[3] ) ) : 0;
if ( ! $max_numbered_placeholder || $args_count < $max_numbered_placeholder ) {
return '';
@@ -1673,35 +1529,8 @@ class wpdb {
}
}
$args_escaped = array();
foreach ( $args as $i => $value ) {
if ( in_array( $i, $arg_identifiers, true ) ) {
$args_escaped[] = $this->_escape_identifier_value( $value );
} elseif ( is_int( $value ) || is_float( $value ) ) {
$args_escaped[] = $value;
} else {
if ( ! is_scalar( $value ) && ! is_null( $value ) ) {
wp_load_translations_early();
_doing_it_wrong(
'wpdb::prepare',
sprintf(
/* translators: %s: Value type. */
__( 'Unsupported value type (%s).' ),
gettype( $value )
),
'4.8.2'
);
// Preserving old behavior, where values are escaped as strings.
$value = '';
}
$args_escaped[] = $this->_real_escape( $value );
}
}
$query = vsprintf( $query, $args_escaped );
array_walk( $args, array( $this, 'escape_by_ref' ) );
$query = vsprintf( $query, $args );
return $this->add_placeholder_escape( $query );
}
@@ -3950,13 +3779,11 @@ class wpdb {
* @since 2.7.0
* @since 4.1.0 Added support for the 'utf8mb4' feature.
* @since 4.6.0 Added support for the 'utf8mb4_520' feature.
* @since 6.1.0 Added support for the 'identifier_placeholders' feature.
*
* @see wpdb::db_version()
*
* @param string $db_cap The feature to check for. Accepts 'collation', 'group_concat',
* 'subqueries', 'set_charset', 'utf8mb4', 'utf8mb4_520',
* or 'identifier_placeholders'.
* 'subqueries', 'set_charset', 'utf8mb4', or 'utf8mb4_520'.
* @return bool True when the database feature is supported, false otherwise.
*/
public function has_cap( $db_cap ) {
@@ -4001,12 +3828,6 @@ class wpdb {
}
case 'utf8mb4_520': // @since 4.6.0
return version_compare( $db_version, '5.6', '>=' );
case 'identifier_placeholders': // @since 6.1.0
/*
* As of WordPress 6.1, wpdb::prepare() supports identifiers via '%i',
* e.g. table/field names.
*/
return true;
}
return false;
+11 -122
View File
@@ -494,11 +494,9 @@ class Tests_DB extends WP_UnitTestCase {
$this->assertTrue( $wpdb->has_cap( 'collation' ) );
$this->assertTrue( $wpdb->has_cap( 'group_concat' ) );
$this->assertTrue( $wpdb->has_cap( 'subqueries' ) );
$this->assertTrue( $wpdb->has_cap( 'identifier_placeholders' ) );
$this->assertTrue( $wpdb->has_cap( 'COLLATION' ) );
$this->assertTrue( $wpdb->has_cap( 'GROUP_CONCAT' ) );
$this->assertTrue( $wpdb->has_cap( 'SUBQUERIES' ) );
$this->assertTrue( $wpdb->has_cap( 'IDENTIFIER_PLACEHOLDERS' ) );
$this->assertSame(
version_compare( $wpdb->db_version(), '5.0.7', '>=' ),
$wpdb->has_cap( 'set_charset' )
@@ -1717,135 +1715,26 @@ class Tests_DB extends WP_UnitTestCase {
false,
"'{$placeholder_escape}'{$placeholder_escape}s 'hello'",
),
/*
* @ticket 56933.
* When preparing a '%%%s%%', test that the inserted value
* is not wrapped in single quotes between the 2 hex values.
*/
array(
'%%%s%%',
'hello',
false,
"{$placeholder_escape}hello{$placeholder_escape}",
),
array(
"'%-'#5s' '%'#-+-5s'",
array( 'hello', 'foo' ),
false,
"'hello' 'foo##'",
),
array(
'SELECT * FROM %i WHERE %i = %d;',
array( 'my_table', 'my_field', 321 ),
false,
'SELECT * FROM `my_table` WHERE `my_field` = 321;',
),
array(
'WHERE %i = %d;',
array( 'evil_`_field', 321 ),
false,
'WHERE `evil_``_field` = 321;', // To quote the identifier itself, then you need to double the character, e.g. `a``b`.
),
array(
'WHERE %i = %d;',
array( 'evil_````````_field', 321 ),
false,
'WHERE `evil_````````````````_field` = 321;',
),
array(
'WHERE %i = %d;',
array( '``evil_field``', 321 ),
false,
'WHERE `````evil_field````` = 321;',
),
array(
'WHERE %i = %d;',
array( 'evil\'field', 321 ),
false,
'WHERE `evil\'field` = 321;',
),
array(
'WHERE %i = %d;',
array( 'evil_\``_field', 321 ),
false,
'WHERE `evil_\````_field` = 321;',
),
array(
'WHERE %i = %d;',
array( 'evil_%s_field', 321 ),
false,
"WHERE `evil_{$placeholder_escape}s_field` = 321;",
),
array(
'WHERE %i = %d;',
array( 'value`', 321 ),
false,
'WHERE `value``` = 321;',
),
array(
'WHERE `%i = %d;',
array( ' AND evil_value', 321 ),
false,
'WHERE `` AND evil_value` = 321;', // Won't run (SQL parse error: "Unclosed quote").
),
array(
'WHERE %i` = %d;',
array( 'evil_value -- ', 321 ),
false,
'WHERE `evil_value -- `` = 321;', // Won't run (SQL parse error: "Unclosed quote").
),
array(
'WHERE `%i`` = %d;',
array( ' AND true -- ', 321 ),
false,
'WHERE `` AND true -- ``` = 321;', // Won't run (Unknown column '').
),
array(
'WHERE ``%i` = %d;',
array( ' AND true -- ', 321 ),
false,
'WHERE ``` AND true -- `` = 321;', // Won't run (SQL parse error: "Unclosed quote").
),
array(
'WHERE %2$i = %1$d;',
array( '1', 'two' ),
false,
'WHERE `two` = 1;',
),
array(
'WHERE \'%i\' = 1 AND "%i" = 2 AND `%i` = 3 AND ``%i`` = 4 AND %15i = 5',
array( 'my_field1', 'my_field2', 'my_field3', 'my_field4', 'my_field5' ),
false,
'WHERE \'`my_field1`\' = 1 AND "`my_field2`" = 2 AND ``my_field3`` = 3 AND ```my_field4``` = 4 AND ` my_field5` = 5', // Does not remove any existing quotes, always adds it's own (safer).
),
array(
'WHERE id = %d AND %i LIKE %2$s LIMIT 1',
array( 123, 'field -- ', false ),
true, // Incorrect usage.
null, // Should be rejected, otherwise the `%1$s` could use Identifier escaping, e.g. 'WHERE `field -- ` LIKE field -- LIMIT 1' (thanks @vortfu).
),
array(
'WHERE %i LIKE %s LIMIT 1',
array( "field' -- ", "field' -- " ),
false,
"WHERE `field' -- ` LIKE 'field\' -- ' LIMIT 1", // In contrast to the above, Identifier vs String escaping is used.
),
);
}
public function test_allow_unsafe_unquoted_parameters() {
global $wpdb;
$sql = 'WHERE (%i = %s) OR (%10i = %10s) OR (%5$i = %6$s)';
$values = array( 'field_a', 'string_a', 'field_b', 'string_b', 'field_c', 'string_c' );
$default = $wpdb->allow_unsafe_unquoted_parameters;
$wpdb->allow_unsafe_unquoted_parameters = true;
// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
$part = $wpdb->prepare( $sql, $values );
$this->assertSame( 'WHERE (`field_a` = \'string_a\') OR (` field_b` = string_b) OR (`field_c` = string_c)', $part ); // Unsafe, unquoted parameters.
$wpdb->allow_unsafe_unquoted_parameters = false;
// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
$part = $wpdb->prepare( $sql, $values );
$this->assertSame( 'WHERE (`field_a` = \'string_a\') OR (` field_b` = \' string_b\') OR (`field_c` = \'string_c\')', $part );
$wpdb->allow_unsafe_unquoted_parameters = $default;
}
/**
* @dataProvider data_escape_and_prepare
*/