CVE-2007-4893

wp-admin/admin-functions.php in Wordpress before 2.2.3 and Wordpress multi-user (MU) before 1.2.5a does not properly verify the unfiltered_html privilege, which allows remote attackers to conduct cross-site scripting (XSS) attacks via modified data to (1) post.php or (2) page.php with a no_filter field.

Weakness

The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.

Affected Software

Potential Mitigations

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330]
• Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]
• Use the “double-submitted cookie” method as described by Felten and Zeller:
• When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user’s machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same.
• Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult.
• This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/111.html
• https://cwe.mitre.org/data/definitions/462.html
• https://cwe.mitre.org/data/definitions/467.html
• https://cwe.mitre.org/data/definitions/62.html

References

• http://fedoranews.org/updates/FEDORA-2007-214.shtml
• http://secunia.com/advisories/26771
• http://secunia.com/advisories/26796
• http://trac.wordpress.org/ticket/4720
• http://wordpress.org/development/2007/09/wordpress-223/
• http://www.securityfocus.com/bid/25639
• http://www.vupen.com/english/advisories/2007/3132
• https://bugzilla.redhat.com/show_bug.cgi?id=285831
• https://exchange.xforce.ibmcloud.com/vulnerabilities/36576