CVE-2025-59295: Windows 10 1507 Buffer Overflow Vulnerability

CVE-2025-59295 Overview

CVE-2025-59295 is a heap-based buffer overflow vulnerability affecting Internet Explorer across a wide range of Microsoft Windows operating systems. This memory corruption flaw enables an unauthorized attacker to execute arbitrary code over a network, potentially leading to complete system compromise. The vulnerability requires user interaction, such as visiting a malicious website, but can result in significant impact to confidentiality, integrity, and availability of affected systems.

Critical Impact

Remote code execution via heap overflow in Internet Explorer could allow attackers to gain full control of affected systems, execute malware, steal sensitive data, or pivot to additional network resources.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 22H2, 23H2, 24H2, 25H2)
• Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, 2025

Discovery Timeline

• October 14, 2025 - CVE-2025-59295 published to NVD
• October 17, 2025 - Last updated in NVD database

Technical Details for CVE-2025-59295

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), a memory corruption condition that occurs when Internet Explorer writes data beyond the boundaries of a heap-allocated buffer. When processing specially crafted web content, the browser fails to properly validate buffer sizes before writing data to heap memory, allowing attackers to overwrite adjacent memory structures.

Successful exploitation can corrupt heap metadata, function pointers, or other critical data structures, enabling attackers to redirect program execution to malicious code. The network-accessible nature of this vulnerability makes it particularly dangerous, as victims only need to be lured to a malicious website or tricked into clicking a link in a phishing email.

The vulnerability affects both 32-bit (x86) and 64-bit (x64) architectures across the entire supported Windows ecosystem, from legacy Windows Server 2008 through the latest Windows 11 and Windows Server 2025 releases. This broad attack surface increases the potential impact across enterprise environments.

Root Cause

The root cause of CVE-2025-59295 is improper bounds checking during heap memory operations within Internet Explorer. When the browser processes malformed or excessively large input data, it fails to validate that the destination buffer can accommodate the incoming data. This oversight allows an attacker-controlled payload to overflow the allocated heap region, corrupting adjacent memory and potentially enabling code execution.

Attack Vector

The attack vector for this vulnerability is network-based, requiring user interaction. An attacker would typically:

1. Craft a malicious webpage or HTML content containing exploit code targeting the heap overflow
2. Deliver the exploit via phishing emails, malicious advertisements, or compromised websites
3. Wait for a victim using Internet Explorer on a vulnerable Windows system to access the content
4. Upon rendering the malicious content, trigger the heap overflow to gain code execution in the context of the current user

The exploitation mechanism manipulates heap memory allocation and deallocation patterns to place attacker-controlled data in predictable memory locations, then triggers the overflow to overwrite critical heap structures. Modern heap exploitation techniques such as heap spraying and use-after-free chaining may be employed to achieve reliable code execution.

Detection Methods for CVE-2025-59295

Indicators of Compromise

• Unexpected crashes or error messages from Internet Explorer (iexplore.exe) particularly when browsing
• Unusual memory consumption patterns or heap corruption signatures in Windows Event logs
• Detection of suspicious JavaScript or HTML content designed to spray heap memory
• Network connections to suspicious domains originating from Internet Explorer processes

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions like SentinelOne to detect heap corruption and exploit attempts in real-time
• Enable Windows Defender Exploit Guard with Attack Surface Reduction (ASR) rules targeting browser-based exploits
• Monitor process behavior for anomalous child process creation from iexplore.exe
• Implement network intrusion detection signatures for known Internet Explorer exploit patterns

Monitoring Recommendations

• Enable detailed Application Event logging on Windows systems to capture browser crash events
• Configure SentinelOne Deep Visibility for monitoring memory protection violations and anomalous process behavior
• Review web proxy logs for access to newly registered domains or known malicious infrastructure
• Implement browser telemetry collection to identify potential exploitation attempts before successful compromise

How to Mitigate CVE-2025-59295

Immediate Actions Required

• Apply the latest Microsoft security updates from the October 2025 Patch Tuesday release immediately
• Consider disabling Internet Explorer via Group Policy in favor of Microsoft Edge or other modern browsers
• Implement network segmentation to limit potential lateral movement from compromised endpoints
• Educate users about phishing risks and the dangers of clicking untrusted links

Patch Information

Microsoft has released security updates to address CVE-2025-59295. Organizations should consult the Microsoft Security Update Guide for CVE-2025-59295 for detailed patch information and download links. Apply patches to all affected Windows versions including Windows 10, Windows 11, and Windows Server editions through Windows Update, WSUS, or SCCM.

Workarounds

• Disable Internet Explorer via Windows Features or Group Policy (Computer Configuration > Administrative Templates > Windows Components > Internet Explorer)
• Enable Enhanced Protected Mode in Internet Explorer to add additional sandboxing protections
• Configure Internet Explorer Security Zones to restrict Active Scripting on untrusted sites
• Deploy Microsoft Defender Application Guard (MDAG) to isolate browsing sessions from the host operating system

# Disable Internet Explorer via PowerShell (Windows 10/11)
Disable-WindowsOptionalFeature -FeatureName Internet-Explorer-Optional-amd64 -Online -NoRestart

# Enable Enhanced Protected Mode via Registry
reg add "HKCU\Software\Microsoft\Internet Explorer\Main" /v "Isolation" /t REG_SZ /d "PMEM" /f