CVE-2024-43496: Microsoft Edge Chromium RCE Vulnerability

CVE-2024-43496 Overview

CVE-2024-43496 is a remote code execution vulnerability in Microsoft Edge (Chromium-based). Microsoft classifies the flaw under [CWE-787] (Out-of-Bounds Write), a memory corruption weakness that can lead to arbitrary code execution in the browser process. Successful exploitation requires user interaction, such as visiting a malicious webpage or opening crafted content.

The vulnerability carries a CVSS 3.1 score of 8.8 and has an EPSS exploitation probability of 0.619% (70.4 percentile). Microsoft has published a security advisory and addressed the issue in updated Edge releases.

Critical Impact
Attackers can achieve remote code execution in the context of the browser, leading to full compromise of confidentiality, integrity, and availability when a user loads attacker-controlled content.

Affected Products

Microsoft Edge (Chromium-based) versions prior to the September 2024 security update
Windows installations running the affected Edge build
macOS and Linux installations running the affected Edge build

Discovery Timeline

2024-09-19 - CVE-2024-43496 published to NVD
2024-09-23 - Last updated in NVD database

Technical Details for CVE-2024-43496

Vulnerability Analysis

The vulnerability is a remote code execution flaw in Microsoft Edge (Chromium-based) tied to an out-of-bounds write condition [CWE-787]. An attacker hosts crafted web content that, when rendered by the vulnerable browser, triggers memory corruption in a Chromium component. The corruption permits the attacker to execute arbitrary code within the browser process boundary.

Because the attack vector is network-based and requires user interaction, exploitation typically occurs through drive-by browsing, phishing links, or malicious advertisements. The scope remains unchanged, meaning code executes with the privileges of the current user running the browser.

Root Cause

The root cause is an out-of-bounds write in a Chromium-based Edge component. Software writes data past the end of an allocated buffer, corrupting adjacent memory structures. Attackers shape the corruption to overwrite control data such as function pointers or virtual table entries, redirecting execution to attacker-controlled code.

Microsoft has not published deep technical internals for this specific issue. Refer to the Microsoft CVE-2024-43496 Advisory for vendor-specified affected builds.

Attack Vector

The attack requires the victim to interact with malicious content rendered by Edge. Typical delivery methods include malicious websites, compromised legitimate sites, malvertising, and embedded iframes. No authentication or elevated privileges are required from the attacker. The user simply needs to load the crafted page or content.

No public proof-of-concept exploit is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2024-43496

Indicators of Compromise

Unexpected Edge browser crashes or repeated renderer process terminations correlating with visits to untrusted URLs
Child processes spawned by msedge.exe that are inconsistent with normal browser behavior, such as command interpreters or scripting hosts
Outbound network connections from Edge to known malicious hosts following navigation to an untrusted site

Detection Strategies

Inventory all endpoints and confirm installed Edge versions against the fixed builds listed in the Microsoft advisory
Monitor process lineage for suspicious children of msedge.exe, including powershell.exe, cmd.exe, and rundll32.exe
Correlate browser crash telemetry with web proxy logs to identify pages that trigger renderer faults

Monitoring Recommendations

Enable EDR telemetry for browser process behavior and memory anomalies on all user endpoints
Forward Edge crash dumps and Windows Error Reporting events to a central SIEM for analysis
Track DNS and HTTP egress for newly observed domains accessed shortly before browser crashes

How to Mitigate CVE-2024-43496

Immediate Actions Required

Update Microsoft Edge to the latest stable channel build through edge://settings/help or managed update channels
Verify that automatic updates are enabled and not blocked by group policy or network restrictions
Restart browser sessions after patch installation to ensure the updated binary is loaded

Patch Information

Microsoft has released an updated build of Microsoft Edge (Chromium-based) that addresses CVE-2024-43496. Administrators should consult the Microsoft CVE-2024-43496 Advisory for the exact fixed version and apply the update across all managed endpoints.

Workarounds

Restrict browsing to trusted sites through enterprise web proxy categorization until patches are deployed
Deploy Microsoft Defender SmartScreen and enable enhanced security mode in Edge to reduce exploitation surface
Use group policy to enforce minimum Edge versions across the fleet via the MinimumVersion policy or update channel configuration

bash

# Configuration example: enforce Edge update channel via Group Policy registry
reg add "HKLM\SOFTWARE\Policies\Microsoft\EdgeUpdate" /v UpdateDefault /t REG_DWORD /d 1 /f
reg add "HKLM\SOFTWARE\Policies\Microsoft\EdgeUpdate" /v AutoUpdateCheckPeriodMinutes /t REG_DWORD /d 60 /f