WordPress Privileges Unchecked in admin.php and Multiple Information Disclosures
Core Security Technologies - CoreLabs Advisory
1. Advisory Information
- WordPress Privileges Unchecked in admin.php and Multiple Information Disclosures
- Advisory ID
- Advisory URL
- Date published
- Date of last update
- Vendors contacted
- Release mode
- Coordinated release
- Fernando Arnaboldi and José Orlicki
2. Vulnerability Information
- Local file include, Privileges unchecked, Cross site scripting (XSS), Information disclosure
- Remotely Exploitable
- Locally Exploitable
- Bugtraq ID
- 35581, 35584
- CVE Name
- CVE-2009-2334, CVE-2009-2335, CVE-2009-2336
3. Vulnerability Description
WordPress is a web application written in PHP that allows the easy installation of a flexible weblog on any computer connected to the Internet. WordPress 2.7 reached more than 6 million downloads during June 2009 .
4. Vulnerable packages
- WordPress 2.8 and previous
- WordPress MU 2.7.1 and previous, used in WordPress.com
5. Non-vulnerable packages
- WordPress 2.8.1
- WordPress MU 2.8.1, used in WordPress.com
6. Vendor Information, Solutions and Workarounds
Mitigation for the Privileges Unchecked vulnerability (suggested by Core Security): this vulnerability may be mitigated by controlling access to files inside the wp-admin folder. Access can be prohibited by using Apache access control mechanism (.htaccess file), see guideline for more information .
These vulnerabilities were discovered and researched by Fernando Arnaboldi and José Orlicki from Core Security Technologies. Further research was made by Jose Orlicki from Core Security Technologies.
8. Technical Description / Proof of Concept Code
In the last few years several security bugs were found in WordPress . During 2008, the big amount of bugs reported by researchers lead to exploitation by blog spammers . During 2009, a new round of attacks has appeared and security researchers are reporting new bugs or wrongly fixed previously-reported bugs . A path traversal in local files included by admin.php has been fixed  but, in our case, we report that administrative privileges are still unchecked when accessing any PHP file inside a plugin folder.
8.2. Access Control Roles
WordPress has a privilege model where any user has an assigned role . Regarding plugins only users characterized by the role Administrator can activate plugins. Notice that only the blog hosting owner can add new plugins because these must by copied inside the host filesystem. The roles Editor, Author or Subscriber (the latter has the least privileges) cannot activate plugins, edit plugins, update plugins nor delete plugins installed by an Administrator. Besides that, the configuration of specific plugins is a grey area because there is no distinguished capability assigned .
This can be modified by the administrator in Membership/Anyone can register.
8.3. Privileges Unchecked in admin.php?page= Plugin Local File Includes (CVE-2009-2334, BID 35581)
No privileges are checked on WordPress plugins configuration PHP modules using parameter page when we replace options-general.php with admin.php. The same thing happens when replacing other modules such as plugins.php with admin.php. Basic information disclosure is done this way. For example, with the following URL a user with no privileges can see the configuration of plugin Collapsing Archives, if installed.
Instead of the following allowed URL.
Another example of this information disclosure is shown on Akismet, a plugin shipped by default with WordPress.
All plugins we have tested are vulnerable to this kind of information disclosure, but in many of them the PHP files accessed just crashed. On the other hand, for example, with capability import, privileges are checked inside admin.php:
if ( ! current_user_can('import') ) wp_die(__('You are not allowed to import.'));
More dangerous scenarios exist, all of them can be exploited by users with the Subscriber role, the least privileged.
8.4. Abuse example: XSS in plugin configuration module
But replacing the PHP file with the generic admin.php any blog user can modify this configuration.
This is the worst scenario that we found for the vulnerability.
8.5. Abuse example: viewing WP Security Scanner Plugin Dashboard
If installed, the WordPress Security Scanner Plugin dashboard can be viewed similarly by any user besides the administrator using the plugin configuration page URL without modification. This dashboard includes common default blog configuration settings that are insecure and should be modified by the blog administrator or hosting.
8.6. Abuse example: reconfiguring WP-IDS, a WordPress Hardening Project
If installed, the *Intrusion Detection System Plugin (WPIDS)* can be reconfigured accessed with the same vulnerability.
This gives an attacker the possibility to disable many features of the plugin, for example reactivate the forgotten password feature and reactivate the XML-RPC blog interface. Also you can deny the weblog service by configuring this plugin to be overly sensitive, blocking any request. However the plugin cannot be totally disabled because the essential IDS parameters Maximum impact to ignore bad requests and Minimum impact to sanitize bad requests are verified on the server side of the blog and cannot be distorted to deactivate the sanitizing or blocking features of the web IDS plugin.
8.7. Other Information Disclosures (CVE-2009-2335, CVE-2009-2336, BID 35584)
WordPress discriminates bad password from bad user logins, this reduces the complexity of a brute force attack on WordPress blogs login (CVE-2009-2335, BID 35584). The same user information disclosure happens when users use the forgotten mail interface to request a new password (CVE-2009-2336, same BID 35584). These information disclosures seem to be previously reported  but the WordPress team is refusing to modify them alleging *user convenience*.
Default installation of WordPress 2.7.1 leaks the name of the user posting entries inside the HTML of the blog.
<small>June 3rd, 2009 <!-- by leakedusername --></small>
Also several administrative modules give to anyone the complete path where the web application is hosted inside the server. This may simplify or enable other malicious attacks. An example follows.
Notice: Use of undefined constant ABSPATH - assumed 'ABSPATH' in [WP_LEAKED_PATH]wp-settings.php on line 110 Notice: Use of undefined constant ABSPATH - assumed 'ABSPATH' in [WP_LEAKED_PATH]wp-settings.php on line 112 Warning: require(ABSPATHwp-includes/compat.php) [function.require]: failed to open stream: No such file or directory in [WP_LEAKED_PATH]wp-settings.php on line 246 Fatal error: require() [function.require]: Failed opening required 'ABSPATHwp-includes/compat.php' (include_path='.;[PHP_LEAKED_PATH]php5pear') in [WP_LEAKED_PATH]wp-settings.php on line 246
9. Report Timeline
- 2009-06-04: Core Security Technologies notifies the WordPress team of the vulnerabilities (firstname.lastname@example.org) and offers a technical description encrypted or in plain-text. Advisory is planned for publication on June 22th.
- 2009-06-08: Core notifies again the WordPress team of the vulnerability.
- 2009-06-10: The WordPress team asks Core for a technical description of the vulnerability in plain-text.
- 2009-06-11: Technical details sent to WordPress team by Core.
- 2009-06-11: WordPress team notifies Core that a fix was produced and is available to Core for testing. WordPress team asserts that password and username discrimination as well as username leakage are known and will not be fixed because they are convenient for the users.
- 2009-06-12: Core tells the WordPress team that the patch will be tested by Core as a courtesy as soon as possible. It also requests confirmation that WordPress versions 2.8 and earlier, and WordPress.com, are vulnerable to the flaws included in the advisory draft CORE-2009-0515.
- 2009-06-12: WordPress team confirms that WordPress 2.8 and earlier plus WordPress.com are vulnerable to the flaws included in the advisory draft.
- 2009-06-17: Core informs the WordPress team that the patch is only fixing one of the four proof of concept abuses included in the advisory draft. Core reminds the WordPress team that the advisory is scheduled to be published on June 22th but a new schedule can be discussed.
- 2009-06-19: Core asks for a new patched version of WordPress, if available, and notifies the WordPress team that the publication of the advisory was re-scheduled to June 30th.
- 2009-06-19: WordPress team confirms they have a new patch that has the potential to break a lot of plugins.
- 2009-06-29: WordPress team asks for a delayance on advisory CORE-2009-0515 publication until July 6th, when WordPress MU version will be patched.
- 2009-06-29: Core agrees to delay publication of advisory CORE-2009-0515 until July 6th.
- 2009-06-29: Core tells the WordPress team that other administrative PHP modules can also be rendered by non-administrative users, such as module admin-post.php and link-parse-opml.php.
- 2009-07-02: WordPress team comments that admin.php and admin-post.php are intentionally open and plugins can choose to hook either privileged or unprivileged actions. They also comment that unprivileged access to link-parse-opml.php is benign but having this file open is bad form.
- 2009-07-02: Core sends the WordPress team a new draft of the advisory and comments that there is no capability specified in Worpress documentation for configuring plugins. Also control of actions registered by plugins is not enforced. Core also notices that the privileges unchecked bug in admin.php?page= is fixed on WordPress 2.8.1-beta2 latest development release.
- 2009-07-06: Core requests WordPress confirmation of the release date of WordPress 2.8.1 and WordPress MU 2.8.
- 2009-07-07: WordPress team confirms that a release candidate of WordPress 2.8.1 is made available to users and that the advisory may be published.
- 2009-07-06: Core requests WordPress confirmation of the release date of WordPress MU and WordPress MU new version numbers.
- 2009-07-07: WordPress team release WordPress 2.8.1 RC1 to its users.
- 2009-07-08: WordPress team confirms that WordPress MU 2.8.1 will be made available as soon WordPress 2.8.1 is officially released. Probably July 8th or 9th.
- 2009-07-08: The advisory CORE-2009-0515 is published.
 WordPress vulnerabilities in CVE database
 SecuriTeam List of WordPress Vulnerabilities
 WordPress Vulnerability - YBO Interactive Blog
 bablooO/blyat attacks on WP 2.7.0 and 2.7.1
 Security breach - xkcd blog
 securityvulns.com WordPress vulnerabilities digest in English
 WordPress Roles and Capabilities
 WordPress Download Counter
 WordPress Intrusion Detection System Plugin
 Hardening WordPress with htaccess
11. About CoreLabs
CoreLabs, the research center of Core Security Technologies, is charged with anticipating the future needs and requirements for information security technologies. We conduct our research in several important areas of computer security including system vulnerabilities, cyber attack planning and simulation, source code auditing, and cryptography. Our results include problem formalization, identification of vulnerabilities, novel solutions and prototypes for new technologies. CoreLabs regularly publishes security advisories, technical papers, project information and shared software tools for public use at: http://www.coresecurity.com/corelabs.
12. About Core Security Technologies
Core Security Technologies develops strategic solutions that help security-conscious organizations worldwide develop and maintain a proactive process for securing their networks. The company's flagship product, CORE IMPACT, is the most comprehensive product for performing enterprise security assurance testing. CORE IMPACT evaluates network, endpoint and end-user vulnerabilities and identifies what resources are exposed. It enables organizations to determine if current security investments are detecting and preventing attacks. Core Security Technologies augments its leading technology solution with world-class security consulting services, including penetration testing and software security auditing. Based in Boston, MA and Buenos Aires, Argentina, Core Security Technologies can be reached at 617-399-6980 or on the Web at http://www.coresecurity.com.
The contents of this advisory are copyright (c) 2009 Core Security Technologies and (c) 2009 CoreLabs, and may be distributed freely provided that no fee is charged for this distribution and proper credit is given.
14. PGP/GPG Keys
This advisory has been signed with the GPG key of Core Security Technologies advisories team, which is available for download at http://www.coresecurity.com/files/attachments/core_security_advisories.asc.