WordPress Advanced Access Manager 2.8.2 File Write / Code Execution

`Details  
================  
Software: Advanced Access Manager  
Version: 2.8.2  
Homepage: http://wordpress.org/plugins/advanced-access-manager/  
Advisory report: https://security.dxw.com/advisories/advanced-access-manager-allows-admin-users-to-write-arbitrary-text-to-arbitrary-locations-which-could-lead-to-arbitrary-code-execution-etc/  
CVE: CVE-2014-6059  
CVSS: 6.5 (Medium; AV:N/AC:L/Au:S/C:P/I:P/A:P)  
  
Description  
================  
Advanced Access Manager allows admin users to write arbitrary files and execute arbitrary php  
  
Vulnerability  
================  
Advanced Access Manager allows writing arbitrary content to arbitrary files. Depending on the server configuration this could allow arbitrary code execution, overwriting core WordPress files and e.g. blanking wp-config.php. In other configurations this could lead to overwriting files in the uploads directory.  
  
Proof of concept  
================  
  
Visit http://localhost/wp-admin/admin.php?page=aam-configpress  
Press “Save” (this creates the “aam_configpress” option)  
Visit http://localhost/wp-admin/options.php  
Set “aam_configpress” to “test.php”  
Press “Save Changes”  
Visit http://localhost/wp-admin/admin.php?page=aam-configpress again  
Enter “<?php phpinfo();” into the textarea (without the quotes)  
Press “Save”  
Visit http://localhost/wp-content/aam/test.php  
  
Note that there is no restriction on using “../” in the “aam_configpress” option so depending on server configuration you could create files anywhere on the filesystem.  
This attack could be scripted to allow upload of binary files, including executable files.  
  
Mitigations  
================  
Upgrade to version 2.8.3 or later  
  
Disclosure policy  
================  
dxw believes in responsible disclosure. Your attention is drawn to our disclosure policy: https://security.dxw.com/disclosure/  
  
Please contact us on [email protected] to acknowledge this report if you received it via a third party (for example, [email protected]) as they generally cannot communicate with us on your behalf.  
  
This vulnerability will be published if we do not receive a response to this report with 14 days.  
  
Timeline  
================  
  
2014-08-20: Discovered  
2014-09-01: Reported to author via email  
2014-09-01: Requested CVE  
2014-09-01: Developer responded  
2014-09-02: Developer reported the issue fixed  
2014-09-03: Advisory published  
  
  
  
Discovered by dxw:  
================  
Tom Adams  
Please visit security.dxw.com for more information.  
  
  
  
  
`