Advisory: Directory Traversal in DevExpress ASP.NET File Manager During a penetration test RedTeam Pentesting discovered a directory traversal vulnerability in DevExpress' ASP.NET File Manager and File Upload. Attackers are able to read arbitrary files by specifying a relative path. Details ======= Product: DevExpress ASPxFileManager Control for WebForms and MVC Affected Versions: DevExpress ASPxFileManager v10.2 to v13.2.8 Fixed Versions: DevExpress ASPxFileManager v13.2.9 Vulnerability Type: Directory Traversal Security Risk: high Vendor URL: https://www.devexpress.com/Products/NET/Controls/ASP/File-Upload-Explorer/ Vendor Status: fixed version released Advisory URL: https://www.redteam-pentesting.de/advisories/rt-sa-2014-006 Advisory Status: published CVE: CVE-2014-2575 CVE URL: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-2575 Introduction ============ "The DevExpress ASP.NET Subscription includes a standalone Multi-File Upload Manager for WebForms and MVC and a pre-built File Manager for WebForms; built so you can instantly introduce file management capabilities in your next web application." (from DevExpress' Homepage) More Details ============ The ASPX File Manager component is prone to a directory traversal vulnerability. Attackers with access to the File Manager component can read arbitrary files on the same partition as the shared directory. A common request to download a file via the File Manager component requires multiple HTTP-Post parameters: __EVENTTARGET=ctl00%24ContentPlaceHolder1%24ASPxFileManager1 __EVENTARGUMENT=13%7C<file.ext> __EVENTVALID= The parameter __EVENTARGUMENT=13|<file.ext> specifies a file download and the file which is to be downloaded. Attackers may also request files outside of the shared directory by prepending a relative path to a parent directory. Proof of Concept ================ By requesting files with a relative path, files otherwise not available will be accessible through the File Manager component. Depending on the shared directory and the webserver configuration, the webserver configuration file might for example be accessible through the File Manager component: __EVENTARGUMENT=13|../../web.config Other sensitive operating system files could be affected, too. Example exploit: ------------------------------------------------------------------------ curl --data __EVENTTARGET=ctl00%24ContentPlaceHolder1%24ASPxFileManager1\ "&__EVENTARGUMENT=13%7C../../web.config&=&__EVENTVALID" \ http://example.com/FileManagerComponent.aspx ------------------------------------------------------------------------ The request above will download the specified file. Workaround ========== Instead of a physical file system provider, a database file system provider with limited access permissions could be used. Fix === Update ASPxFileManager control to DevExpress libraries version v13.2.9. Security Risk ============= The risk is estimated to be high. This vulnerability allows attackers to access arbitrary files on the same partition as the File Manager's root directory. This may allow attackers to read sensitive information like the webserver configuration. Timeline ======== 2014-03-10 Vulnerability identified 2014-03-21 Customer approved disclosure to vendor 2014-03-21 CVE number requested and assigned 2014-03-25 Vendor noProduct Security Response Centertified 2014-04-11 Customer opened support ticket with vendor 2014-04-17 Vendor released fixed version 2014-04-17 Vendor released security advisory to customers 2014-06-05 Advisory released References ========== Vendor Security Advisory: http://security.devexpress.com/de7c4756/?id=ff8c1703126f4717993ac3608a65a2e2 RedTeam Pentesting GmbH ======================= RedTeam Pentesting offers individual penetration tests, short pentests, performed by a team of specialised IT-security experts. Hereby, security weaknesses in company networks or products are uncovered and can be fixed immediately. As there are only few experts in this field, RedTeam Pentesting wants to share its knowledge and enhance the public knowledge with research in security related areas. The results are made available as public security advisories. More information about RedTeam Pentesting can be found at https://www.redteam-pentesting.de. -- http://security.devexpress.com/de7c4756/?id=ff8c1703126f4717993ac3608a65a2e2 RedTeam Pentesting GmbH Tel.: +49 241 510081-0 Dennewartstr. 25-27 Fax : +49 241 510081-99 52068 Aachen https://www.redteam-pentesting.de Germany Registergericht: Aachen HRB 14004 Geschftsfhrer: Patrick Hof, Jens Liebchen