WordPress SSRF攻击修复方案

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wordpress /wp-includes/http.php文件中的wp_http_validate_url函数对输入IP验证不当，导致黑客可构造类似于012.10.10.10这样的畸形IP绕过验证，进行SSRF。

修复方法：(http.php为修复后的)

$ diff http.php.2018-07-23 http.php
533c533
<               $same_host = strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] );
---
>                if ( isset( $parsed_home['host'] ) ) { $same_host = ( strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] ) || 'localhost' === strtolower( $parsed_url['host'] ) ); } else { $same_host = false; } ;
549c549
<                       if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0]
---
>                        if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0]  || 0 === $parts[0]

#if ( preg_match( '#^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$#', $host ) ) {
        if ( preg_match('#^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d|0+\d+)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$#', $host) ) {
            $ip = $host;
}

$ diff http.php.2018-07-23 http.php

533c533

< $same_host = strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] );

---

> if ( isset( $parsed_home['host'] ) ) { $same_host = ( strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] ) || 'localhost' === strtolower( $parsed_url['host'] ) ); } else { $same_host = false; } ;

549c549

< if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0]

---

> if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0] || 0 === $parts[0]

#if ( preg_match( '#^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$#', $host ) ) {

if ( preg_match('#^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d|0+\d+)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$#', $host) ) {

$ip = $host;

}

SourceByrd's Weblog-https://note.t4x.org/other/wordpress-fix-ssrf/

# diff http.php http.php.bk 
533c533
<                if ( isset( $parsed_home['host'] ) ) { $same_host = ( strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] ) || 'localhost' === strtolower( $parsed_url['host'] ) ); } else { $same_host = false; } ;
---
>               $same_host = strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] );
550c550
<                        if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0]  || 0 === $parts[0]
---
>                       if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0]

# diff http.php http.php.bk

533c533

< if ( isset( $parsed_home['host'] ) ) { $same_host = ( strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] ) || 'localhost' === strtolower( $parsed_url['host'] ) ); } else { $same_host = false; } ;

---