SEC Consult Security Advisory < 20091217-0 > title: Authentication bypass and file manipulation in Sitecore Staging Module products: Sitecore Staging Module vulnerable version: Sitecore Staging Module <= 5.4.0 rev.080625 fixed version: Staging 5.4.0 rev.091111 impact: critical homepage: http://www.sitecore.net/en/Products/Sitecore-CMS.aspx found: 2009-09-07 by: L. Weichselbaum / SEC Consult / www.sec-consult.com Vendor description: ------------------- Sitecore CMS makes it effortless to create content and experience rich websites that help you achieve your business goals such as increasing sales and search engine visibility, while being straight-forward to integrate and administer. Sitecore lets you deliver sites that are highly scalable, robust and secure. Whether you're focused on marketing, development and design, or providing site content, Sitecore delivers for you. The main purpose of the Sitecore Staging module is to update two or more Sitecore installations across a firewall. source: http://www.sitecore.net/en/Products.aspx http://sdn.sitecore.net/upload/sdn5/sitecore6modules/staging/ staging-module-installation-and-configuration-guide.pdf Vulnerability overview/description: ----------------------------------- The Staging Webservice (normally found in "/sitecore modules/staging/ service/api.asmx") used for transmitting files between the Sitecore Master and Slave Server is vulnerable to authentication bypass and therefore * files can be uploaded in arbitrary directories on the server * files can be downloaded from arbitrary directories on the server * directory listings of the whole server can be received * the webserver cache can be deleted An attacker is able to upload a shell, modify or delete sensitive data or gain the whole source code of the application. Furthermore it is possible to retrieve directory listings of directories of the whole server and the webroot. All these actions are performed with the rights of the webserver user. One tested server allowed us to compromise the whole server by uploading a shell into the webroot. Proof of concept: ----------------- Authentication bypass and file manipulation =========================================== To exploit this vulnerability, the example of "api.asmx?op=Upload" can be used in a slightly modified form. The parameters "Username" and "Password" can be set at random, but they must not be empty. The parameter "File" contains the base64 encoded content of the file which should be uploaded. For the parameters "append" and "isEncrypted" the value "false" is most suitable. In "Destination" the location of the file on the remote system can be specified. The following POST-request creates a file named test.txt in C:\temp. It would also be possible to upload a shell into the Webroot. POST /sitecore%20modules/staging/service/api.asmx HTTP/1.1 Host: hostToExploit Content-Type: application/soap+xml; charset=utf-8 Content-Length: 599 <?xml version="1.0" encoding="utf-8"?> <soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope"> <soap12:Body> <Upload xmlns="http://Sitecore/modules/Staging/API/"> [Soap-Stuff] </Upload> </soap12:Body> </soap12:Envelope> The same applies to the webservice operations "Download", "List" and "Clear Cache". Vulnerable versions: -------------------- Sitecore Staging Module * <= v5.4.0 rev.080625 Vendor contact timeline: ------------------------ 2009-10-09: Contacting Sitecore. 2009-10-12: Reply from Sitecore. 2009-10-12: Preliminary advisory with full vulnerability details was sent to Sitecore. 2009-12-02: Requested status of the planned security fixes. 2009-12-03: Reply from Sitecore, fixes are now in second iteration in their QA department and they expect to release this before Christmas. 2009-12-03: Reply from Sitecore, vulnerabilities have been fixed and new version has been released. 2009-12-16: Final version of the advisory sent to Sitecore and release date was scheduled. 2009-12-16: Reply from Sitecore. 2009-12-17: Release of the advisory. Solution: --------- Update to Sitecore Staging Module v5.4.0 rev.091111 Workaround: ----------- Delete the Staging Webservice (normally found in "/sitecore modules/ staging/service/api.asmx") to prevent arbitrary file manipulation. The Sitecore Staging Module can thereby only use FTP for transmitting files between the Sitecore Master and Slave with the Sitecore Staging Module. Advisory URL: ------------- https://www.sec-consult.com/advisories_e.html#a63 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Unternehmensberatung GmbH Office Vienna Mooslackengasse 17 A-1190 Vienna Austria Tel.: +43 / 1 / 890 30 43 - 0 Fax.: +43 / 1 / 890 30 43 - 25 Mail: research at sec-consult dot com www.sec-consult.com SEC Consult conducts periodical information security workshops on ISO 27001/BS 7799 in cooperation with BSI Management Systems. For more information, please refer to https://www.sec-consult.com/academy_e.html EOF L. Weichselbaum / @2009