r3dxpl0it/cve-2018-15473

OpenSSH 7.7 - Username Enumeration

CVE-2018-15473

OpenSSH 7.7 - Username Enumeration

Method

The attacker can try to authenticate a user with a malformed packet (for example, a truncated packet), and:

• if the user is invalid (it does not exist), then userauth_pubkey() returns immediately, and the server sends an SSH2_MSG_USERAUTH_FAILURE to the attacker;

• if the user is valid (it exists), then sshpkt_get_u8() fails, and the server calls fatal() and closes its connection to the attacker.

Usage

Usage of the Library is Very Simple and it can be used just in few lines

python <target> --port <port> --userlist <username_file> 

Vulnerable Systems

• Redhat Enterprise Linux 7
• Redhat Enterprise Linux 6
• Trustix Secure Enterprise Linux 2.0
• Trustix Secure Linux 2.2
• Trustix Secure Linux 2.1
• Trustix Secure Linux 2.0
• Redhat Enterprise Linux 5
• OpenSSH OpenSSH 3.4
• OpenSSH OpenSSH 3.3
• Openwall Openwall GNU/*/Linux (Owl)-current
• OpenSSH OpenSSH 2.9
• FreeBSD FreeBSD 4.6 -RELEASE
• FreeBSD FreeBSD 4.6
• FreeBSD FreeBSD 4.5 -RELEASE
• FreeBSD FreeBSD 4.5
• OpenSSH OpenSSH 2.5.2
• Caldera OpenUnix 8.0
• Caldera UnixWare 7.1.1
• Wirex Immunix OS 6.2
• OpenSSH OpenSSH 2.5.1
• NetBSD NetBSD 1.5.1
• S.u.S.E. Linux Database Server 0
• S.u.S.E. Linux Firewall on CD
• S.u.S.E. SuSE eMail Server III
• SCO Open Server 5.0.6 a
• SCO Open Server 5.0.6
• SCO Open Server 5.0.5
• SCO Open Server 5.0.4
• SCO Open Server 5.0.3
• SCO Open Server 5.0.2
• SCO Open Server 5.0.1
• SCO Open Server 5.0
• SuSE Linux 7.3
• SuSE Linux 7.2
• SuSE Linux 7.1
• SuSE SUSE Linux Enterprise Server 7
• OpenSSH OpenSSH 2.5
• OpenSSH OpenSSH 2.3
• SuSE Linux 7.0 sparc
• SuSE Linux 7.0 ppc
• SuSE Linux 7.0 i386
• SuSE Linux 7.0 alpha
• SuSE Linux 6.4 ppc
• SuSE Linux 6.4 i386
• SuSE Linux 6.4 alpha
• OpenSSH OpenSSH 2.1.1
• SuSE Linux 7.0 sparc
• SuSE Linux 7.0 ppc
• SuSE Linux 7.0 i386
• SuSE Linux 7.0 alpha
• OpenSSH OpenSSH 2.1
• OpenSSH OpenSSH 1.2.3
• Blue Coat Systems Security Gateway OS 2.1.5001 SP1
• OpenSSH OpenSSH 1.2.2
• OpenSSH OpenSSH 7.7
• OpenSSH OpenSSH 7.6
• OpenSSH OpenSSH 7.4
• OpenSSH OpenSSH 7.3
• OpenSSH OpenSSH 7.2
• OpenSSH OpenSSH 7.1
• OpenSSH OpenSSH 7.0
• OpenSSH OpenSSH 6.9
• OpenSSH OpenSSH 6.8
• OpenSSH OpenSSH 6.7
• NetBSD NetBSD 1.5.1
• S.u.S.E. Linux Database Server 0
• S.u.S.E. Linux Firewall on CD
• S.u.S.E. Linux Live-CD for Firewall
• S.u.S.E. SuSE eMail Server III
• SCO Open Server 5.0.6 a
• SCO Open Server 5.0.6
• SCO Open Server 5.0.5
• SCO Open Server 5.0.4
• SCO Open Server 5.0.3
• SCO Open Server 5.0.2
• SCO Open Server 5.0.1
• SCO Open Server 5.0
• SuSE Linux 7.3
• SuSE Linux 7.2
• SuSE Linux 7.1
• SuSE SUSE Linux Enterprise Server 7
• OpenSSH OpenSSH 6.6
• OpenSSH OpenSSH 6.5
• OpenSSH OpenSSH 6.4
• OpenSSH OpenSSH 6.3
• OpenSSH OpenSSH 6.2
• OpenSSH OpenSSH 6.1
• OpenSSH OpenSSH 6.0
• OpenSSH OpenSSH 5.8
• OpenSSH OpenSSH 5.7
• OpenSSH OpenSSH 5.6
• OpenSSH OpenSSH 5.5
• OpenSSH OpenSSH 4.5
• OpenSSH OpenSSH 1.127
• OpenSSH OpenSSH 1.126
• OpenBSD OpenSSH 6.0
• OpenBSD OpenSSH 3.0.2
• OpenBSD OpenSSH 2.5.2
• OpenBSD OpenSSH 2.3.1
• OpenBSD OpenBSD 2.8
• OpenBSD OpenBSD 2.7
• OpenBSD OpenBSD 2.6
• OpenBSD OpenSSH 2.1
• OpenBSD OpenSSH 1.2.3
• Debian Linux 2.2 sparc
• Debian Linux 2.2 powerpc
• Debian Linux 2.2 arm
• Debian Linux 2.2 alpha
• Debian Linux 2.2 68k
• Debian Linux 2.2
• OpenBSD OpenSSH 1.2
• OpenBSD OpenSSH 6.6
• OpenBSD OpenSSH 6.5
• OpenBSD OpenSSH 6.4
• OpenBSD OpenSSH 5.9
• OpenBSD OpenSSH 5.8
• OpenBSD OpenSSH 5.7
• OpenBSD OpenSSH 5.4
• OpenBSD OpenSSH 5.2
• OpenBSD OpenSSH 5.1
• OpenBSD OpenSSH 4.9
• OpenBSD OpenSSH 4.8
• OpenBSD OpenSSH 4.7
• OpenBSD OpenSSH 4.6
• OpenBSD OpenSSH 4.4
• OpenBSD OpenSSH 4.3
• OpenBSD OpenSSH 4.2
• OpenBSD OpenSSH 4.1
• OpenBSD OpenSSH 4.0

cve-2018-15473's Issues

no attribute 'userList'

python openssh.py 10.10.10.1 --port 22 --userlist unix_users.txt

Initially i got Traceback (most recent call last):
File "openssh.py", line 81, in
elif args.userList:
AttributeError: 'Namespace' object has no attribute 'userList'

there is a line 81 has userList, it should be userlist

paramiko.auth_handler issue

root@kali:~/Downloads/CVE-2018-15473# python openssh.py <OMITTED> --port 22 --userlist ~/Downloads/ssh-userlist.txt 
Traceback (most recent call last):
  File "openssh.py", line 17, in <module>
    old_parse_service_accept = paramiko.auth_handler.AuthHandler._handler_table[paramiko.common.MSG_SERVICE_ACCEPT]
TypeError: 'property' object has no attribute '__getitem__'
root@kali:~/Downloads/CVE-2018-15473# pip list |grep paramiko
paramiko                      2.6.0         
root@kali:~/Downloads/CVE-2018-15473# pip list |grep cryptography
cryptography                  2.6.1    

'BadUsername' is not defined

python openssh.py 10.10.10.1 --port 22 --userlist unix_users.txt

Traceback (most recent call last):
File "openssh.py", line 90, in
results = pool.map(checkUsername, usernames)
File "/usr/lib/python2.7/multiprocessing/pool.py", line 253, in map
return self.map_async(func, iterable, chunksize).get()
File "/usr/lib/python2.7/multiprocessing/pool.py", line 572, in get
raise self._value
NameError: global name 'BadUsername' is not defined