Problems with RDP connectivity

Hello, since I couple of days, I am having severe problems connecting to windows boxes on Academy using Remote Desktop Protocol. The problem started during the Windows Privilege Escalation Module and is also happening with “Shells and Payloads”.

I have tried the 3 major RDP clients, rdesktop xfreerdp & reminna. VPN connection was renewed and resetted a couple of times.

However, these problems are also occurring inside the Parrot-pwnbox, it is therefore not related to my local Kali installation. Is anyone here who is currently having similar issues?

I am again stuck with exactly the same problem in module “Active Directory Enumeration and Attacks”.
I cannot RDP into the MS01 box, the given credentials are refused. The problem is independent of using my personal Kali Machine or HTB Pwnbox.

HTB support suggested to renew my VPN connection which of course did not improve anything. I am stuck with this situation for almost one week. Any idea what could be the issue here?

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When I connect to a Windows machine with xfreerdp, it takes less than 10 seconds to connect.
Is there a solution?

I had the same problems and found that it ran better at certain times. I suspect that we share the academy computer with others. There is a maximum number of connections allowed!

At least that is my guess!

I had the same problems and found that it ran better at certain times. I suspect that we share the academy computer with others. There is a maximum number of connections allowed!

Yes, sometimes I realize Pwnbox would get slower and slower. There are some time-dependent resource bottlenecks in the infrastructure.

When I connect to a Windows machine with xfreerdp, it takes less than 10 seconds to connect.
Is there a solution?

Changing VPN to a different region is the only thing that helps in this situation.

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So I had a similar problem - particularly when the password had special characters, and I was attempting to use xfreerdp.

When the password was something like

AnotherC0mpl3xP4$$

it must be encompassed in single quotes.

I don’t know if this is obvious to others - thought I’d share in case it saves others a heap of time.

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Thank you very much, details that are not found.

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was having the same trouble for the last couple days no matter what time i tried to use RDP. This tip worked ^

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thanks

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If the problem occurs with both Windows and Parrot-pwnbox, then I think this may indicate a problem on the HTB Academy side
Try contacting the HTB Academy support service. They will be able to diagnose your problem. They usually have a support team that can help with technical questions like this. Apart from this, you can also try other connection methods or check for updates for your RDP clients.

you are a legend i was at the exact same question and googled for this

I am still not able to do the RDP, tried RDP and all other RDP clients

rdesktop -u htb-student -p ‘Academy_student_AD!’ 10.129.67.140:3389

Reposted from reddit, worked for me:

Just press Enter when on black screen. You are in fact on Windows login screen waiting for input to login to your Windows account. It Just doesnt show… I was stuck on this for 3 days sometimes getting in and not knowing why:)) Until it clicked and I felt rollecoaster of emotions…

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Your a f*cking goat and you dont even know it

Thank you!

Man, this is perfect. I have been pulling my hair out for months, switching VPNs, using different services and this works perfectly. Just hit enter on the black screen!!

When connecting to a machine via RDP through a VPN connection, you may encounter a black, unresponsive screen. In my case, I could only see the mouse cursor, but the screen remained black even after pressing Enter multiple times. This issue persisted across different RDP clients including xfreerdp, remmina, and rdesktop.

While switching to a different VPN server worked in some cases, I found a more reliable solution by adjusting the VPN connection parameters.

Solution: Use this command to connect to VPN:
sudo openvpn --config ~/Downloads/academy-regular.ovpn --mssfix 1200 --tun-mtu 1500

Why this works: The black screen often occurs because VPN packets are too large and get broken into pieces (fragmented) during transmission. When these fragmented packets arrive at their destination, they don’t get reassembled correctly, causing RDP to fail to display properly. The command above fixes this by:

  • --mssfix 1200: Limits the size of data packets to prevent fragmentation
  • --tun-mtu 1500: Sets an appropriate tunnel size that matches standard network configurations

This solution ensures data packets remain intact during transmission, allowing RDP to receive and display the remote desktop properly.

xfreerdp /u:eagle\bob /p:Slavi123 /v:172.16.18.25 /dynamic-resolution