CVE-2025-49742: Windows 10 1507 Graphics Component RCE Flaw

CVE-2025-49742 Overview

CVE-2025-49742 is an integer overflow vulnerability in the Microsoft Graphics Component. An authenticated local attacker can trigger the flaw to execute arbitrary code with elevated privileges on the target host. Microsoft assigned the issue a CVSS 3.1 base score of 7.8 and mapped it to CWE-122: Heap-based Buffer Overflow, indicating the integer wraparound leads to an undersized heap allocation and subsequent memory corruption.

The vulnerability affects a broad range of Windows client and server releases, including Windows 10, Windows 11, and Windows Server versions from 2008 through 2025. Microsoft published the advisory on July 8, 2025.

Critical Impact

A local, authenticated attacker can achieve arbitrary code execution in the Microsoft Graphics Component, leading to full compromise of confidentiality, integrity, and availability on affected Windows systems.

Affected Products

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

Discovery Timeline

• 2025-07-08 - CVE-2025-49742 published to NVD and Microsoft advisory released
• 2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-49742

Vulnerability Analysis

CVE-2025-49742 resides in the Microsoft Graphics Component, a shared subsystem that parses and renders graphics primitives, fonts, and image data on behalf of user-mode and kernel-mode callers. The component performs arithmetic on attacker-influenced size values before allocating a heap buffer. When the arithmetic wraps around the integer boundary, the resulting allocation is smaller than the data ultimately written into it, producing a heap-based buffer overflow (CWE-122).

Exploitation requires local access and low-privileged authentication, but no user interaction. Successful exploitation yields code execution in the context of the vulnerable component, which can be used to escalate privileges from a standard user to SYSTEM.

Root Cause

The root cause is an unchecked arithmetic operation on a length or count field used to size a heap allocation. When the computed value exceeds the maximum representable integer, it wraps to a small value. The subsequent copy operation uses the original, larger length, overflowing the undersized buffer and corrupting adjacent heap metadata or object pointers.

Attack Vector

The attack vector is local (AV:L). An attacker with an authenticated shell on the target — for example through Remote Desktop, a compromised service account, or a foothold obtained via phishing — supplies a malformed graphics object or invokes an affected API with crafted size parameters. The overflow corrupts controlled heap memory, giving the attacker a path to hijack execution flow and run code with elevated privileges. No verified public proof-of-concept is available at the time of writing, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

See the Microsoft CVE-2025-49742 Advisory for vendor-specific technical details.

Detection Methods for CVE-2025-49742

Indicators of Compromise

• Unexpected crashes or Windows Error Reporting entries referencing graphics libraries such as win32k.sys, win32kfull.sys, or gdi32.dll on unpatched hosts.
• Creation of new SYSTEM-context processes spawned by low-privileged users shortly after graphics-related faults.
• Anomalous privilege elevations recorded in Security event ID 4672 for accounts that do not normally receive administrative privileges.

Detection Strategies

• Monitor Windows Error Reporting and kernel crash dumps for repeated faults in the Microsoft Graphics Component, which may indicate exploitation attempts against the integer overflow.
• Correlate process creation events (Sysmon Event ID 1) with the parent-child relationship of a standard user process spawning cmd.exe, powershell.exe, or other administrative tools under SYSTEM.
• Detect unusual loading of graphics-related DLLs into non-graphical processes as a signal of exploit staging.

Monitoring Recommendations

• Baseline normal graphics subsystem behavior on servers and endpoints, then alert on statistically significant deviations in crash frequency or process spawning patterns.
• Track patch compliance across all Windows versions listed in the advisory using vulnerability management tooling and reconcile with EDR telemetry.
• Forward Windows Security, System, and Sysmon logs to a centralized SIEM to enable cross-host correlation of local privilege escalation attempts.

How to Mitigate CVE-2025-49742

Immediate Actions Required

• Apply the July 2025 Microsoft security updates that address CVE-2025-49742 to all affected Windows client and server systems.
• Prioritize patching on multi-user systems such as Remote Desktop Session Hosts, Citrix servers, and jump hosts where local access is most readily obtained.
• Audit local accounts and remove unnecessary interactive logon rights to reduce the pool of principals capable of triggering the flaw.

Patch Information

Microsoft has released security updates for all affected Windows client and server versions. Refer to the Microsoft CVE-2025-49742 Advisory for the applicable KB article numbers for each Windows build and install the corresponding cumulative update through Windows Update, WSUS, or the Microsoft Update Catalog.

Workarounds

• No official vendor workaround is documented; applying the security update is the supported remediation.
• Enforce the principle of least privilege and restrict interactive or Remote Desktop access to trusted administrators on unpatched hosts.
• Deploy application control policies such as Windows Defender Application Control (WDAC) or AppLocker to limit which binaries unprivileged users can execute while patching is scheduled.

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