Attacking machines

HTB Content
1

I’m running Nmap scans against the target machines and the only output i get from multiple machines is as follows.

sudo nmap -sV -A -O 10.10.11.148
[sudo] password for su8z3r0:
Starting Nmap 7.91 ( https://nmap.org ) at 2022-06-29 08:55 AEST
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.69 seconds

I’ve made sure I’m correctly connected to the VPN and still cannot work out what could be causing this.

I edited the.ovpn file last night to switch the connection method to TCP, and that fixed the problem last night, but as of right now I’m facing the same issue.

Any suggestions on how to fix this?

Regards.

2

There is a problem with openvpn at the moment. Type ifconfig in command line to see if you are connected to the ‘tun0’ network with an address like 10.10.xxx.xxx. If not, edit your downloaded ovpn file, replace ‘cipher AES-128-CBC’ with ‘data-ciphers-fallback AES-128-CBC’. Note that in your terminal tab when you commence the connection, it should read something like ‘initialisation completed’ if the connection is successful. Keep that tab permanently open in your terminal.

3

I’ve noticed the problem. For some reason, after the initialisation sequence is completed, my connection is being reset and continuously restarting.

The output is as follows.

2022-06-29 21:37:54 Preserving previous TUN/TAP instance: tun8
2022-06-29 21:37:54 Initialization Sequence Completed
2022-06-29 21:37:55 Connection reset, restarting [0]
2022-06-29 21:37:55 SIGUSR1[soft,connection-reset] received, process restarting
2022-06-29 21:37:55 Restart pause, 5 second(s)

ifconfig returns the following;

tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 fe80::eeec:55a6:61a4:18e8 prefixlen 64 scopeid 0x20
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 17 bytes 816 (816.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun1: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 fe80::4376:26ad:6f24:7bde prefixlen 64 scopeid 0x20
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 17 bytes 816 (816.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun2: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 fe80::b195:6e64:b457:31a4 prefixlen 64 scopeid 0x20
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 35 bytes 2380 (2.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun3: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
inet6 fe80::3e6d:5046:d4b8:dd4 prefixlen 64 scopeid 0x20
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 17 bytes 816 (816.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun4: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
inet6 fe80::86a9:9cd7:ecbc:5d68 prefixlen 64 scopeid 0x20
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 32 bytes 2212 (2.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun5: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
inet6 fe80::5750:a97:bc67:ffd prefixlen 64 scopeid 0x20
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 31 bytes 2164 (2.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun6: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
inet6 fe80::fda8:a1fc:2a78:4577 prefixlen 64 scopeid 0x20
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 31 bytes 2164 (2.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun7: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 fe80::e6a8:4f81:ffbc:fc84 prefixlen 64 scopeid 0x20
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 791 bytes 150364 (146.8 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun8: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.16.9 netmask 255.255.254.0 destination 10.10.16.9
inet6 fe80::9225:ce52:8656:28e prefixlen 64 scopeid 0x20
inet6 dead:beef:4::1007 prefixlen 64 scopeid 0x0
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 7 bytes 336 (336.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

The .ovpn file already contained.

data-ciphers-fallback AES-128-CBC

When I had this problem last night, I solved it by switching the connection method to TCP and that fixed the problem. However, this seems like a different issue. I am not sure what is causing it. Did you experience the same issue?