CVE-2024-7533: Google Chrome Use-After-Free Vulnerability

CVE-2024-7533 Overview

CVE-2024-7533 is a use after free vulnerability in the Sharing component of Google Chrome on iOS. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. The vulnerability exists in Chrome versions prior to 127.0.6533.99 and has been classified with high severity by the Chromium security team.

Critical Impact

Remote attackers can exploit heap corruption through malicious web content, potentially leading to arbitrary code execution, data theft, or complete compromise of the affected browser session.

Affected Products

• Google Chrome on iOS prior to version 127.0.6533.99
• Apple iPhone OS (as the underlying operating system)
• Chrome Sharing feature component

Discovery Timeline

• August 6, 2024 - CVE-2024-7533 published to NVD
• August 12, 2024 - Last updated in NVD database

Technical Details for CVE-2024-7533

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption issue that occurs when a program continues to reference memory after it has been freed. In the context of the Chrome Sharing feature on iOS, this flaw creates an exploitable condition where freed memory can be manipulated by an attacker through carefully crafted HTML content.

Use after free vulnerabilities in browser engines are particularly dangerous because browsers routinely process untrusted content from the web. When the Sharing component attempts to access memory that has already been deallocated, the attacker can potentially control what data occupies that memory location, leading to heap corruption and possible code execution.

The vulnerability requires user interaction (such as visiting a malicious webpage), but once triggered, the attack can occur over the network without requiring any authentication or prior access to the target system.

Root Cause

The root cause of CVE-2024-7533 lies in improper memory management within the Sharing component of Chrome on iOS. Specifically, the vulnerability occurs when an object is freed but references to that object are not properly invalidated. When these dangling pointers are subsequently dereferenced, the browser accesses memory that may have been reallocated for a different purpose or controlled by the attacker.

This type of vulnerability typically arises from complex object lifecycle management where multiple code paths can trigger object destruction while other components still hold references to the freed memory.

Attack Vector

The attack vector for CVE-2024-7533 is network-based, requiring a victim to visit a malicious webpage containing specially crafted HTML content. The attack sequence involves:

1. An attacker creates a malicious HTML page designed to trigger the use after free condition in Chrome's Sharing feature
2. The victim navigates to the malicious page using Chrome on iOS
3. The crafted HTML triggers the memory corruption vulnerability
4. The attacker exploits the heap corruption to potentially achieve arbitrary code execution or data exfiltration

The attack does not require any special privileges and can be executed against any user running a vulnerable version of Chrome on iOS. For detailed technical information, see the Chromium Issue Tracker Entry.

Detection Methods for CVE-2024-7533

Indicators of Compromise

• Unexpected browser crashes or instability when accessing web content, particularly content involving sharing functionality
• Unusual memory consumption patterns in Chrome browser processes
• Chrome crash reports indicating heap corruption or memory access violations in the Sharing component
• Browser history showing visits to suspicious or unknown domains shortly before anomalous behavior

Detection Strategies

• Monitor for Chrome crash dumps that indicate use after free conditions or heap corruption
• Implement endpoint detection rules to identify exploitation attempts targeting browser memory corruption vulnerabilities
• Deploy network monitoring to detect traffic to known malicious domains serving exploit code
• Use behavioral analysis to identify abnormal Chrome process behavior following web browsing activity

Monitoring Recommendations

• Enable Chrome's built-in crash reporting to capture and analyze browser stability issues
• Monitor endpoint logs for signs of post-exploitation activity following browser sessions
• Implement web filtering to block access to untrusted or suspicious domains
• Review Chrome version deployment across managed iOS devices to identify unpatched instances

How to Mitigate CVE-2024-7533

Immediate Actions Required

• Update Google Chrome on iOS to version 127.0.6533.99 or later immediately
• Enable automatic updates for Chrome on all iOS devices to ensure timely patching
• Educate users about the risks of visiting untrusted websites until patches are applied
• Consider temporarily restricting access to non-essential web browsing on sensitive devices

Patch Information

Google has addressed this vulnerability in Chrome version 127.0.6533.99. The fix properly manages object lifecycles within the Sharing component to prevent the use after free condition. Organizations should prioritize updating all Chrome installations on iOS devices to this version or later.

For official patch details, refer to the Google Chrome Update Announcement.

Workarounds

• If immediate patching is not possible, consider temporarily using an alternative browser until Chrome can be updated
• Implement strict web filtering policies to limit exposure to potentially malicious content
• Disable or restrict access to the Sharing feature in Chrome if enterprise management tools allow
• Deploy network security controls to block access to known malicious domains

# Verify Chrome version on iOS
# Navigate to: Chrome App > Settings > About Chrome
# Ensure version is 127.0.6533.99 or higher

# For enterprise deployments, verify Chrome version policy:
# Use Mobile Device Management (MDM) to enforce minimum Chrome version
# Example policy enforcement via MDM configuration profile