JScript Runtime error in Windows 11 24H2

Question

Hi team,

We have been facing issues with Windows 11 24H2 Upgrade with our JScript code.

As we observed the reason being is the Jscript.DLL, We get to know that old Jcript.DLL is being replaced with new Jscript9Legacy.DLL for remediation of vulnerabilities.

And this new DLL doesn't have all support for functions/features supported by old DLL. especially dynamic link between method calls in JScript and its definition which is written in Delphi for windows application.

Can you please share the information or any links which can be referred to get all the details about the vulnerabilities in which functions/features it was reported for Old Jscript.DLL.

Answer 1

I am also facing the same issue with new Jscript9legacy.dll in Windows11 24H2 version. But in 23H2 windows 11 everything is working fine and its loading Jscript.dll to run the Jscript code from our application. Is there any solution to fix these issues instead of adding JscriptReplacement from Registry?

Can we get these fixes in upcoming patch releases?

Answer 2

Sorry My English is weak.

I was in a similar situation

There is a problem with "ByteArray" in JScript.dll

If the length of data is an odd number, an error will occur

(VB Script)binary length 1 -> (JScript)ByteArray length 0 (Why?)

(VB Script)binary length 3 -> (JScript)ByteArray length 2 (Why?)

[VB Script]

binary = MidB(a , (PosEnd + 4), PosClose - (PosEnd + 4) - 2) 
//<---Print binary length is 3

Set b= CreateBinary()
b.ByteArray = binary 
//<----- Print b.ByteArray length is 2, why?


[JScript]
function CreateBinary()
{ 
	return new Init() 
}
function Init()
{
	this.ByteArray = null
}

Answer 3

There is a JScript-based MVC framework of classic asp.

https://github.com/sometiny/MoAspEnginer

It is well running on the windows 7 or 10，and Server 2016/2019, but not on Windows 11 24H2.

The error message is this bellow:

The JScript script engine version on Windows 10 is JScript 5.8.16384

The JScript script engine version on Windows 11 is JScript 11.0.16384