Termsrvdll Windows Server — 2019
termsrv.dll is a critical RDS component; any variation from the official version in Server 2019 should be considered dangerous or non-compliant.
Modifying system files can cause "Blue Screen of Death" (BSOD) errors or prevent the Remote Desktop service from starting after Windows Updates. Always back up the original file. Step 1: Backup and Permissions termsrvdll windows server 2019
After applying a Windows Server 2019 cumulative update, an older termsrvdll may remain due to incomplete installation. This creates hash mismatches with the licensing service, leading to unpredictable behavior. termsrv
: It optimizes how the "screen" is sent to the client, reducing the data required to maintain a high-quality, fluid visual experience even over slower network connections. 3. Native Multi-Session Management Step 1: Backup and Permissions After applying a
Modifying system files can cause instability, security vulnerabilities, or crashes during Windows Updates.
Accidental deletion, malware infection, or a faulty update.
Nice write up – where can I get the vulnerable app? I checked IOLO’s website and the exploitdb but I can’t find 5.0.0.136
For “System Shield AntiVirus and AntiSpyware” you’ll need to run the downloader which downloads the main installation package but then you’ll need to also request a license. Best just to download “System Mechanic Pro” and install as a trial, this downloads the entire package and no license is required for installation
http://download.iolo.net/sm/15/pro/en/iolo/trial/SystemMechanicPro_15.5.0.61.exe
Hello.
Thanks for this demonstration!
I have a question. With this exploit, can we access to the winlogon.exe and open a handle for read and write memory?
Kind regards,
Yes you can as “SeDebugPrivilege” is also enabled
Why doesn’t it work with csrss.exe?
pHandle = OpenProcess(PROCESS_VM_READ, 0, 428); //my csrss PID
printf(“> pHandle: %d || %s\n”, pHandle, pHandle);
i got: 0 || (null)
It should work, most likely haven’t got the necessary privilege
Oh yes, thanks. But can you help me with “SeDebugPrivilege”. What offset?
Kind regards,
The SeDebugPrivilege is already enabled in this exploit, what you can do it use a previous exploit of mine which uses shellcode being injected in the winlogon process.
Thanks for nice write up. I want to study this case, so I’ve downloaded the link
http://download.iolo.net/sm/15/pro/en/iolo/trial/SystemMechanicPro_15.5.0.61.exe.
And opened amp.sys file with IDA pro, but I could not find the code related to ctl code 0x00226003. How can I find it?
Best just do a text search for 226003 and only one entry will be listed
Thanks! I found with its hex byte ’03 60 22′ in IDA search and reached vulnerable function.