CVE-2024-43579: Microsoft Edge Chromium RCE Vulnerability

CVE-2024-43579 Overview

CVE-2024-43579 is a remote code execution vulnerability in Microsoft Edge (Chromium-based). The flaw is associated with a heap-based buffer overflow condition [CWE-122] in the browser's rendering stack. Successful exploitation allows an attacker to execute arbitrary code in the context of the current user. Exploitation requires user interaction, typically by enticing a target to visit an attacker-controlled web page. Microsoft published the advisory through the Microsoft Security Response Center on October 17, 2024.

Critical Impact

An attacker can achieve remote code execution within the browser process by luring a user to a malicious web page, leading to full compromise of the user's session and stored browser data.

Affected Products

• Microsoft Edge (Chromium-based)
• Edge channels prior to the October 2024 security update
• Systems running Edge as the default or embedded browser component

Discovery Timeline

• 2024-10-17 - CVE-2024-43579 published to NVD
• 2024-10-18 - Last updated in NVD database

Technical Details for CVE-2024-43579

Vulnerability Analysis

The vulnerability is classified as a heap-based buffer overflow [CWE-122] in Microsoft Edge (Chromium-based). A heap overflow occurs when code writes data past the boundary of a dynamically allocated buffer, corrupting adjacent heap memory. Inside a browser, this corruption can be steered to overwrite function pointers, virtual table entries, or JavaScript engine metadata. Attackers can then redirect execution to attacker-controlled shellcode or chain the primitive with a sandbox escape. Microsoft's advisory describes the issue as a remote code execution flaw with network attack vector and required user interaction.

Root Cause

The root cause is improper handling of buffer boundaries on the heap within Edge's Chromium-based code paths. Insufficient size validation before a memory copy or write operation allows attacker-controlled input to exceed the allocated region. The condition is reachable when Edge parses crafted web content delivered over the network.

Attack Vector

Exploitation occurs over the network and requires the victim to interact with malicious content, such as clicking a link or loading a crafted page. The scope is unchanged, meaning code executes within the browser's security context. Confidentiality and integrity impact is High, and availability impact is Low. No authentication is required from the attacker. Public proof-of-concept code is not available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified exploit code is publicly available. For authoritative technical detail, refer to the Microsoft CVE-2024-43579 Advisory.

Detection Methods for CVE-2024-43579

Indicators of Compromise

• Unexpected child processes spawned by msedge.exe, including command shells or script interpreters.
• Edge crash dumps or WerFault.exe events referencing renderer or GPU processes during browsing sessions.
• Outbound network connections from Edge to recently registered or low-reputation domains immediately before a crash.

Detection Strategies

• Monitor process lineage for msedge.exe spawning cmd.exe, powershell.exe, rundll32.exe, or other living-off-the-land binaries.
• Correlate browser crashes with subsequent file write or persistence activity on the same host.
• Inspect web proxy logs for users visiting URLs that immediately precede Edge process anomalies.

Monitoring Recommendations

• Track Edge version inventory across the fleet and flag endpoints running builds prior to the October 2024 security update.
• Alert on disabled or stale browser auto-update services on managed endpoints.
• Enable telemetry collection for renderer process crashes and forward to a centralized analytics platform for correlation.

How to Mitigate CVE-2024-43579

Immediate Actions Required

• Update Microsoft Edge to the latest stable channel build released on or after October 17, 2024.
• Verify auto-update is enabled and that Edge restarts to apply the patch on all managed endpoints.
• Audit endpoints to confirm the fixed version is deployed and report on non-compliant hosts.

Patch Information

Microsoft addressed CVE-2024-43579 in the October 2024 Edge security update. Patch details and the fixed version are documented in the Microsoft CVE-2024-43579 Advisory. Administrators should deploy the update through Microsoft Edge Update, WSUS, Intune, or their standard software distribution platform.

Workarounds

• Restrict browsing to trusted sites using SmartScreen, web filtering, or DNS-layer controls until patching completes.
• Disable JavaScript on untrusted origins via group policy where operational impact is acceptable.
• Enforce least-privilege user accounts so that successful exploitation does not yield administrative rights.

# Verify installed Microsoft Edge version on Windows
reg query "HKLM\SOFTWARE\Microsoft\Edge\BLBeacon" /v version

# Force an Edge update check via the Edge Update service
"%ProgramFiles(x86)%\Microsoft\EdgeUpdate\MicrosoftEdgeUpdate.exe" /ua /installsource scheduler