In a significant move to bolster system security, Microsoft has announced that starting with Windows 11 version 24H2, the legacy JScript engine will be replaced by JScript9Legacy as the default scripting engine. This transition aims to address longstanding vulnerabilities associated with the older JScript engine, enhancing protection against exploits such as cross-site scripting (XSS) and memory corruption bugs.
Introduced in 1996, JScript was Microsoft's implementation of the ECMAScript standard, serving as the backbone for scripting in Internet Explorer and various Windows applications. Over the years, however, it became a target for numerous security exploits due to its outdated architecture. Recognizing these vulnerabilities, Microsoft developed JScript9, a more secure and performance-optimized engine, which was integrated into later versions of Internet Explorer. Building upon this foundation, JScript9Legacy has been adapted to function seamlessly outside the browser environment, ensuring compatibility with legacy scripts while providing enhanced security features.
However, organizations that encounter compatibility issues can revert to the previous JScript engine by contacting Microsoft support for guidance on rolling back to JScript. This flexibility ensures that critical business processes remain uninterrupted while transitioning to the more secure environment provided by JScript9Legacy.
Source: Windows Report Microsoft Replaces JScript with JScript9Legacy for Better Security in Windows 11
Introduced in 1996, JScript was Microsoft's implementation of the ECMAScript standard, serving as the backbone for scripting in Internet Explorer and various Windows applications. Over the years, however, it became a target for numerous security exploits due to its outdated architecture. Recognizing these vulnerabilities, Microsoft developed JScript9, a more secure and performance-optimized engine, which was integrated into later versions of Internet Explorer. Building upon this foundation, JScript9Legacy has been adapted to function seamlessly outside the browser environment, ensuring compatibility with legacy scripts while providing enhanced security features.Key Security Enhancements
The transition to JScript9Legacy brings several critical security improvements:- Mitigation of XSS Attacks: By enforcing stricter execution policies and improving the handling of JavaScript objects, JScript9Legacy significantly reduces the risk of cross-site scripting attacks, a common vector for malicious code injection.
- Prevention of Memory Corruption: The new engine incorporates advanced memory management techniques, effectively mitigating vulnerabilities that could lead to memory corruption and potential remote code execution.
- Alignment with Modern Web Standards: JScript9Legacy is designed to be more compatible with contemporary web standards, ensuring that scripts execute in a secure and predictable manner.
Impact on Users and Organizations
For the majority of users, this update will be seamless. Windows 11 version 24H2 will automatically implement JScript9Legacy as the default scripting engine, and existing scripts are expected to function without requiring modifications. Microsoft has assured that no additional action is necessary to benefit from the improved security features.However, organizations that encounter compatibility issues can revert to the previous JScript engine by contacting Microsoft support for guidance on rolling back to JScript. This flexibility ensures that critical business processes remain uninterrupted while transitioning to the more secure environment provided by JScript9Legacy.
Broader Security Initiatives
The replacement of JScript with JScript9Legacy is part of Microsoft's broader strategy to enhance security across its platforms. In recent updates, Microsoft has introduced features such as Local Security Authority (LSA) protection, NT LAN Manager (NTLM) deprecation, and advancements in key protection using Virtualization-Based Security (VBS). These initiatives reflect a concerted effort to address evolving cyber threats and provide users with a more secure operating system.Conclusion
Microsoft's decision to replace the legacy JScript engine with JScript9Legacy in Windows 11 version 24H2 marks a significant step forward in strengthening system security. By addressing known vulnerabilities and aligning with modern web standards, this update enhances protection against common exploits without disrupting existing workflows. Users and organizations are encouraged to embrace this change to benefit from a more secure and resilient computing environment.Source: Windows Report Microsoft Replaces JScript with JScript9Legacy for Better Security in Windows 11
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