Pentesting

22 - Pentesting SSH/SFTP

Basic Information

SSH or Secure Shell or Secure Socket Shell, is a network protocol that gives users a secure way to access a computer over an unsecured network.

Default port: 22

22/tcp open ssh syn-ack

Enumeration

nc -vn <IP> 22

Public SSH key of server

ssh-keyscan -t rsa <IP> -p <PORT>

Weak Cipher Algorithms

This is discovered by default by nmap. But you can also use sslcan or sslyze.

Shodan

  • ssh

Brute force usernames, passwords and private keys

Username Enumeration

In some versions of OpenSSH you can make a timing attack to enumerate users. You can use a metasploit module in order to exploit this:

msf> use scanner/ssh/ssh_enumusers

Some common ssh credentials here and here and below.

Private/Public Keys BF

If you know some ssh private key that could be used... lets try it. You can use the nmap script:

https://nmap.org/nsedoc/scripts/ssh-publickey-acceptance.html

Or the MSF auxiliary module:

msf> use scanner/ssh/ssh_identify_pubkeys

Known badkeys can be found here:

You should look here in order to search for valid keys for the victim machine.

Default Credentials

Vendor

Usernames

Passwords

APC

apc, device

apc

Brocade

admin

admin123, password, brocade, fibranne

Cisco

admin, cisco, enable, hsa, pix, pnadmin, ripeop, root, shelladmin

admin, Admin123, default, password, secur4u, cisco, Cisco, _Cisco, cisco123, C1sco!23, Cisco123, Cisco1234, TANDBERG, change_it, 12345, ipics, pnadmin, diamond, hsadb, c, cc, attack, blender, changeme

Citrix

root, nsroot, nsmaint, vdiadmin, kvm, cli, admin

C1trix321, nsroot, nsmaint, kaviza, kaviza123, freebsd, public, rootadmin, wanscaler

D-Link

admin, user

private, admin, user

Dell

root, user1, admin, vkernel, cli

calvin, 123456, password, vkernel, Stor@ge!, admin

EMC

admin, root, sysadmin

EMCPMAdm7n, Password#1, Password123#, sysadmin, changeme, emc

HP/3Com

admin, root, vcx, app, spvar, manage, hpsupport, opc_op

admin, password, hpinvent, iMC123, pvadmin, passw0rd, besgroup, vcx, nice, access, config, 3V@rpar, 3V#rpar, procurve, badg3r5, OpC_op, !manage, !admin

Huawei

admin, root

123456, admin, root, Admin123, Admin@storage, Huawei12#$, HwDec@01, hwosta2.0, HuaWei123, fsp200@HW, huawei123

IBM

USERID, admin, manager, mqm, db2inst1, db2fenc1, dausr1, db2admin, iadmin, system, device, ufmcli, customer

PASSW0RD, passw0rd, admin, password, Passw8rd, iadmin, apc, 123456, cust0mer

Juniper

netscreen

netscreen

NetApp

admin

netapp123

Oracle

root, oracle, oravis, applvis, ilom-admin, ilom-operator, nm2user

changeme, ilom-admin, ilom-operator, welcome1, oracle

VMware

vi-admin, root, hqadmin, vmware, admin

vmware, vmw@re, hqadmin, default

Config files

ssh_config
sshd_config
authorized_keys
ssh_known_hosts
known_hosts
id_rsa

SFTP

You can configure SSH to behave as a SFTP server. So, some users will connect to SFTP service (in port 22) instead of to the SSH service.

You can even set a chroot to the SFTP users. A configuration example of SFTP users inside the file /etc/ssh/sshd_config can be seen in the following images.

All the ots-* users will be jailed inside a chroot.

SFTP Tunneling

If you have access to a SFTP server you can also tunnel your traffic through this for example using the common port forwarding:

sudo ssh -L <local_port>:<remote_host>:<remote_port> -N -f <username>@<ip_compromised>

The sftp have the command "symlink". Therefor, if you have writable rights in some folder, you can create symlinks of other folders/files. As you are probably trapped inside a chroot this won't be specially useful for you, but, if you can access the created symlink from a no-chroot service (for example, if you can access the symlink from the web), you could open the symlinked files through the web.

For example, to create a symlink from a new file "froot" to "/":

sftp> symlink / froot

If you can access the file "froot" via web, you will be able to list the root ("/") folder of the system.