CVE-2024-23209: Apple macOS RCE Vulnerability

CVE-2024-23209 Overview

CVE-2024-23209 is a memory handling vulnerability in Apple macOS that allows arbitrary code execution when processing malicious web content. Apple addressed the issue with improved memory handling in macOS Sonoma 14.3. The flaw affects systems running versions prior to 14.3 and is triggered through user interaction with crafted web content. Successful exploitation grants attackers the ability to run arbitrary code on the target system within the context of the affected process.

Critical Impact

Network-based attackers can achieve arbitrary code execution on vulnerable macOS systems when a user processes attacker-controlled web content, with high impact to confidentiality, integrity, and availability.

Affected Products

• Apple macOS versions prior to Sonoma 14.3
• Systems processing untrusted web content via affected components
• macOS endpoints without the January 2024 security update applied

Discovery Timeline

• 2024-01-23 - CVE-2024-23209 published to NVD
• 2026-04-02 - Last updated in NVD database

Technical Details for CVE-2024-23209

Vulnerability Analysis

The vulnerability stems from improper memory handling when macOS processes web content. An attacker crafts malicious content that triggers a memory corruption condition during parsing or rendering. The corruption can be steered to overwrite control data and redirect execution flow. Successful exploitation results in arbitrary code execution within the process handling the web content.

The attack requires user interaction, typically visiting a malicious page or opening a document that loads attacker-controlled web content. The network attack vector and low complexity make this attractive for drive-by and watering-hole campaigns targeting macOS users. The EPSS data places this issue in the upper half of vulnerabilities by exploitation likelihood.

Root Cause

Apple's advisory describes the root cause as a memory handling defect resolved by improved memory management. The CWE is recorded as NVD-CWE-noinfo, indicating Apple has not publicly classified the precise memory weakness class. Memory handling issues in web content processing typically include use-after-free, out-of-bounds access, or type confusion within rendering and JavaScript engines.

Attack Vector

Exploitation occurs remotely over the network. The attacker hosts crafted web content on a controlled domain or injects it into a trusted site. When a macOS user navigates to the resource, the vulnerable component processes the content and triggers the memory corruption. No privileges are required on the target, but user interaction is necessary to load the content.

For technical specifics, see the Apple Support Document HT214061 and the Full Disclosure mailing list post.

Detection Methods for CVE-2024-23209

Indicators of Compromise

• Unexpected child processes spawned from browser or web content rendering processes on macOS hosts running versions earlier than 14.3
• Crash reports in /Library/Logs/DiagnosticReports/ referencing memory access violations in web content handlers
• Outbound connections from rendering processes to previously unseen domains following user web browsing activity
• Persistence artifacts such as new LaunchAgents or LaunchDaemons created shortly after web content was rendered

Detection Strategies

• Inventory macOS endpoints and flag any host reporting a system version earlier than macOS Sonoma 14.3
• Monitor for anomalous process lineage where web content rendering processes spawn shells, scripting interpreters, or installer binaries
• Correlate browser crash telemetry with subsequent suspicious process creation within a short time window
• Apply behavioral identification rules for post-exploitation activity such as credential access, keychain dumping, and lateral movement from macOS endpoints

Monitoring Recommendations

• Ingest endpoint telemetry including process creation, file writes, and network connections from macOS hosts into a centralized analytics platform
• Alert on execution of osascript, curl, bash, or python as children of browser or document rendering processes
• Track creation of files in ~/Library/LaunchAgents/, /Library/LaunchDaemons/, and ~/Library/Application Support/ correlated with browsing sessions
• Maintain a watchlist for domains and IPs serving exploit content reported in threat intelligence feeds

How to Mitigate CVE-2024-23209

Immediate Actions Required

• Update all affected systems to macOS Sonoma 14.3 or later as the primary remediation
• Identify systems that cannot be patched immediately and restrict their exposure to untrusted web content
• Audit recent web content rendering crash logs and process telemetry on unpatched hosts for signs of exploitation attempts
• Communicate the patch requirement to end users and enforce update compliance through MDM policies

Patch Information

Apple resolved CVE-2024-23209 in macOS Sonoma 14.3 through improved memory handling in the affected component. Refer to the Apple security advisory HT214061 and the Apple Support article 120309 for the complete list of fixes included in the update. Apply the update through System Settings or via Mobile Device Management deployment.

Workarounds

• Restrict browsing to trusted sites and disable JavaScript on untrusted origins where business operations allow
• Use content filtering at the network perimeter to block known malicious domains and exploit kit infrastructure
• Enforce least-privilege accounts on macOS endpoints to limit impact if code execution is achieved
• Isolate unpatched systems from sensitive network segments until updates are applied

# Verify the installed macOS version and trigger software update
sw_vers -productVersion
sudo softwareupdate --install --all --restart