CVE-2023-36025: Windows 10 1507 Auth Bypass Vulnerability

CVE-2023-36025 Overview

CVE-2023-36025 is a Windows SmartScreen Security Feature Bypass Vulnerability affecting a wide range of Microsoft Windows operating systems. This vulnerability allows attackers to bypass Windows SmartScreen protections, which are designed to warn users about potentially malicious files downloaded from the internet or untrusted sources. By exploiting this flaw, threat actors can deliver malicious payloads without triggering the standard security warnings that would normally alert users to potential threats.

Critical Impact

This vulnerability is actively exploited in the wild and listed in CISA's Known Exploited Vulnerabilities (KEV) catalog. Attackers can bypass SmartScreen protections to execute malicious code without user awareness, significantly increasing the success rate of phishing and malware delivery campaigns.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 21H2, 22H2, 23H2)
• Microsoft Windows Server 2008, 2012, 2016, 2019, 2022

Discovery Timeline

• November 14, 2023 - CVE-2023-36025 published to NVD
• October 28, 2025 - Last updated in NVD database

Technical Details for CVE-2023-36025

Vulnerability Analysis

This security feature bypass vulnerability affects Windows SmartScreen, a built-in security component that provides reputation-based protection against malicious websites, downloads, and applications. SmartScreen typically displays warning dialogs when users attempt to open files that have been downloaded from the internet and are potentially dangerous, particularly those with the Mark of the Web (MOTW) attribute.

The vulnerability enables attackers to craft specially designed files or links that circumvent SmartScreen's protection mechanisms entirely. When a user interacts with a malicious file exploiting this vulnerability, the expected SmartScreen warning dialog is suppressed, allowing the payload to execute as if it were a trusted file. This significantly reduces the friction for attackers conducting phishing campaigns or distributing malware, as one of Windows' primary user-facing security barriers is rendered ineffective.

The attack requires user interaction, specifically convincing a user to click on a malicious Internet Shortcut (.url) file or a hyperlink pointing to such a file. However, given that SmartScreen bypass removes a critical warning layer, users have no indication that they are about to execute potentially dangerous content.

Root Cause

The root cause of CVE-2023-36025 lies in improper handling of certain file types and URL structures by the SmartScreen security feature. Specifically, the vulnerability can be triggered through specially crafted Internet Shortcut (.url) files that reference malicious content. The SmartScreen component fails to properly validate and apply security checks to these specific file constructs, allowing them to bypass the reputation and warning system.

Attack Vector

The attack vector for this vulnerability is network-based, requiring user interaction. Attackers typically deliver the exploit through:

1. Phishing Emails: Malicious .url files attached to emails or hyperlinks pointing to attacker-controlled resources
2. Compromised Websites: Drive-by download scenarios where users are tricked into downloading malicious shortcut files
3. Social Engineering: Convincing users to click on links that exploit the SmartScreen bypass

When a user clicks on a specially crafted Internet Shortcut file, the referenced payload executes without triggering SmartScreen warnings. This has been observed being used to deploy various malware families including Phemedrone Stealer and other information-stealing malware.

The exploitation flow involves creating an Internet Shortcut file with specific parameters that cause SmartScreen to fail to apply its usual security checks. The malicious shortcut can point to remote resources hosted on attacker infrastructure, enabling the download and execution of malware without the protective warning dialog.

Detection Methods for CVE-2023-36025

Indicators of Compromise

• Suspicious .url Internet Shortcut files with unusual URL parameters or structures
• Network connections to known malicious domains associated with Phemedrone Stealer or similar malware campaigns
• Execution of PowerShell or other scripting engines immediately following .url file interaction
• Presence of information-stealing malware artifacts on endpoints

Detection Strategies

• Monitor for the creation and execution of Internet Shortcut (.url) files from untrusted sources such as email attachments or browser downloads
• Implement endpoint detection rules that alert on suspicious process chains initiated by .url file execution
• Deploy network monitoring to identify connections to known command-and-control infrastructure associated with this vulnerability's exploitation
• Enable Windows Defender attack surface reduction rules to restrict potentially dangerous file types

Monitoring Recommendations

• Configure SIEM rules to correlate .url file downloads with subsequent suspicious process execution
• Implement file integrity monitoring for directories commonly targeted by phishing attacks (Downloads, Desktop, Temp folders)
• Enable detailed logging for Windows SmartScreen events and monitor for bypass attempts
• Review email gateway logs for .url file attachments and block at the perimeter where possible

How to Mitigate CVE-2023-36025

Immediate Actions Required

• Apply Microsoft security updates from the November 2023 Patch Tuesday release immediately
• Ensure all Windows endpoints and servers are configured to receive automatic updates
• Review systems for indicators of compromise, particularly on systems that may not have been patched promptly
• Educate users about the risks of opening unexpected Internet Shortcut files from emails or downloads

Patch Information

Microsoft released patches for CVE-2023-36025 as part of their November 2023 security update. Organizations should immediately apply the appropriate security updates for their Windows versions. Detailed patch information and download links are available from the Microsoft Security Response Center advisory.

Given that this vulnerability is actively exploited in the wild and listed in CISA's Known Exploited Vulnerabilities catalog, patching should be treated as an urgent priority. CISA has mandated that federal agencies remediate this vulnerability, and private organizations should follow similar urgency.

Workarounds

• Block or quarantine .url file attachments at email gateway and web proxy level
• Implement application control policies to restrict execution of files from untrusted sources
• Enable strict Mark of the Web policies and block execution of files that bypass normal security checks
• Consider disabling Internet Shortcut file associations in high-risk environments until patches can be applied

# PowerShell: Check if November 2023 security updates are installed
Get-HotFix | Where-Object {$_.InstalledOn -ge "2023-11-14"} | Format-Table -AutoSize

# Block .url file execution via Group Policy (requires GPO configuration)
# Navigate to: Computer Configuration > Administrative Templates > Windows Components > File Explorer
# Enable: "Do not preserve zone information in file attachments"