CVE-2022-41128: Windows 10 1507 RCE Vulnerability

CVE-2022-41128 Overview

CVE-2022-41128 is a Windows Scripting Languages Remote Code Execution vulnerability that affects a wide range of Microsoft Windows operating systems. This vulnerability exists in the JScript9 scripting engine and allows remote attackers to execute arbitrary code on affected systems when a user visits a specially crafted malicious website or opens a weaponized document. The vulnerability is classified as an out-of-bounds write (CWE-787), which occurs when the scripting engine improperly handles objects in memory.

Critical Impact

This vulnerability is actively exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities catalog, indicating confirmed malicious exploitation. Successful exploitation allows attackers to achieve complete system compromise with the same privileges as the logged-in user.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 20H2, 21H1, 21H2, 22H2)
• Microsoft Windows 11 (versions 21H2, 22H2)
• Microsoft Windows 7 SP1, Windows 8.1
• Microsoft Windows Server 2008 R2 SP1, Server 2012, Server 2012 R2
• Microsoft Windows Server 2016, Server 2019, Server 2022

Discovery Timeline

• 2022-11-09 - CVE-2022-41128 published to NVD
• 2026-01-14 - Last updated in NVD database

Technical Details for CVE-2022-41128

Vulnerability Analysis

This remote code execution vulnerability stems from an out-of-bounds write condition in the Windows Scripting Languages component, specifically within the JScript9 scripting engine (jscript9.dll). The flaw occurs during the processing of specially crafted JavaScript content, where memory bounds checking fails to properly validate write operations.

The vulnerability is particularly dangerous because it can be exploited remotely through user interaction—typically by enticing a victim to visit a malicious webpage using Internet Explorer or by opening a Microsoft Office document that embeds or references malicious script content. Given its presence in CISA's Known Exploited Vulnerabilities catalog, threat actors have already weaponized this vulnerability in real-world attack campaigns.

The attack requires no prior authentication or privileges on the target system, though it does require user interaction to trigger the malicious code execution. Once exploited, an attacker gains code execution context with the same privileges as the current user, potentially leading to complete system compromise if the user has administrative rights.

Root Cause

The root cause is an out-of-bounds write vulnerability (CWE-787) in the JScript9 scripting engine. The engine fails to properly validate memory boundaries when processing certain JavaScript operations, allowing an attacker to write data beyond the allocated buffer. This memory corruption can be leveraged to overwrite critical data structures, manipulate control flow, and ultimately achieve arbitrary code execution.

Attack Vector

The attack vector is network-based and requires user interaction. Exploitation scenarios include:

1. Watering hole attacks: Compromising legitimate websites frequented by target users and injecting malicious JavaScript that triggers the vulnerability
2. Phishing campaigns: Sending emails containing links to attacker-controlled websites hosting exploit code
3. Malicious documents: Embedding or referencing malicious script content within Microsoft Office documents that execute when opened

The vulnerability manifests when the JScript9 engine processes malformed JavaScript objects, causing an out-of-bounds write condition. This memory corruption primitive enables attackers to manipulate program execution flow and inject shellcode for arbitrary code execution. Given the confirmed active exploitation status, organizations should treat this as a high-priority remediation item.

Detection Methods for CVE-2022-41128

Indicators of Compromise

• Anomalous process creation chains originating from iexplore.exe or Microsoft Office applications spawning unexpected child processes such as cmd.exe, powershell.exe, or rundll32.exe
• Suspicious network connections from Internet Explorer or Office processes to unknown or untrusted external IP addresses
• Crash events in jscript9.dll or related JScript engine components captured in Windows Event logs
• Presence of malicious HTML or JavaScript files in browser cache directories containing obfuscated scripting code

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions capable of monitoring for suspicious script engine behavior and memory corruption indicators
• Implement network intrusion detection signatures targeting known exploit payloads and malicious JavaScript patterns associated with CVE-2022-41128
• Monitor for process injection techniques and unusual DLL loading activity originating from browser or Office processes
• Enable Windows Defender Exploit Guard rules to detect and block memory corruption exploitation attempts

Monitoring Recommendations

• Enable detailed Windows Event logging for process creation (Event ID 4688) with command-line auditing to track suspicious process chains
• Configure SIEM correlation rules to alert on Internet Explorer or Office applications executing command interpreters or downloading secondary payloads
• Monitor for JScript9 engine crash events and Application Compatibility Cache modifications that may indicate exploitation attempts
• Regularly review endpoint telemetry for indicators of living-off-the-land techniques commonly used post-exploitation

How to Mitigate CVE-2022-41128

Immediate Actions Required

• Apply Microsoft security updates released in November 2022 Patch Tuesday to all affected Windows systems immediately
• Restrict usage of Internet Explorer and consider migrating to Microsoft Edge or other modern browsers not reliant on the JScript9 engine
• Implement network segmentation to limit lateral movement potential if exploitation occurs
• Educate users about phishing risks and the dangers of opening untrusted documents or clicking suspicious links

Patch Information

Microsoft has released security updates to address this vulnerability as part of the November 2022 security update cycle. The official security guidance and patch downloads are available through the Microsoft Security Response Center (MSRC) advisory. Organizations should prioritize deployment of these patches across all affected Windows client and server systems.

Given the confirmed active exploitation and CISA KEV listing, federal agencies and critical infrastructure organizations are required to remediate this vulnerability within mandated timelines per CISA's Binding Operational Directive. Additional information is available in the CISA Known Exploited Vulnerabilities Catalog.

Workarounds

• Restrict access to jscript9.dll by modifying file system ACLs to limit execution, though this may impact legitimate functionality relying on the JScript9 engine
• Disable Active Scripting in Internet Explorer security zones by configuring Internet Options security settings
• Use Microsoft Enhanced Mitigation Experience Toolkit (EMET) or Windows Defender Exploit Guard to enable exploit mitigations on legacy systems
• Block outbound internet access for systems where Internet Explorer usage is required but cannot be immediately patched

# Example: Restrict JScript9.dll access (run as Administrator)
# Note: This may impact legitimate functionality - test before production deployment
takeown /f "%SystemRoot%\System32\jscript9.dll"
icacls "%SystemRoot%\System32\jscript9.dll" /deny everyone:(X)