CVE-2025-7657: Google Chrome Use After Free Vulnerability

CVE-2025-7657 Overview

CVE-2025-7657 is a use-after-free vulnerability in the WebRTC component of Google Chrome prior to version 138.0.7204.157. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. The vulnerability has been rated as High severity by the Chromium security team.

Critical Impact

Remote attackers can potentially achieve code execution by exploiting heap corruption through malicious web content, requiring only user interaction with a crafted HTML page.

Affected Products

• Google Chrome versions prior to 138.0.7204.157
• Chromium-based browsers using vulnerable WebRTC implementation
• All platforms running affected Chrome versions (Windows, macOS, Linux)

Discovery Timeline

• July 15, 2025 - CVE-2025-7657 published to NVD
• July 16, 2025 - Last updated in NVD database

Technical Details for CVE-2025-7657

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption class where a program continues to use a pointer after it has been freed. In the context of Google Chrome's WebRTC component, this flaw occurs when the browser incorrectly handles memory during WebRTC operations, leaving a dangling pointer that can be manipulated by an attacker.

WebRTC (Web Real-Time Communication) is a browser API that enables real-time audio, video, and data sharing between browsers without requiring plugins. The complexity of managing media streams, peer connections, and data channels creates numerous opportunities for memory management errors, particularly in the handling of session lifecycle events.

Root Cause

The root cause stems from improper memory lifecycle management within the WebRTC subsystem. When certain WebRTC objects are freed during session operations, references to these objects may persist in other parts of the codebase. Subsequent access to these stale references triggers the use-after-free condition, corrupting heap memory and potentially allowing attacker-controlled data to influence program execution.

Attack Vector

Exploitation occurs through a network-based attack vector requiring user interaction. An attacker must craft a malicious HTML page containing JavaScript that manipulates WebRTC APIs in a specific sequence to trigger the use-after-free condition. When a victim visits the attacker-controlled page, the browser processes the crafted WebRTC operations, leading to heap corruption.

The attack chain typically involves:

1. Victim visits a malicious webpage or is redirected through compromised advertising networks
2. The page initiates WebRTC peer connection operations with carefully timed API calls
3. Memory is freed prematurely while references remain active
4. Subsequent operations access the freed memory, enabling heap manipulation
5. Attacker achieves code execution within the browser sandbox context

Due to the sensitive nature of this vulnerability and the lack of verified public exploit code, a detailed technical example is not provided. For technical details, refer to the Google Chrome Update Announcement and Chromium Issue Tracker Entry.

Detection Methods for CVE-2025-7657

Indicators of Compromise

• Unexpected browser crashes, particularly during WebRTC-enabled sessions (video conferencing, screen sharing)
• Chrome crash reports referencing WebRTC components or heap corruption signatures
• Suspicious JavaScript payloads attempting to establish multiple rapid WebRTC peer connections
• Memory access violations logged in system crash dumps from Chrome processes

Detection Strategies

• Monitor for anomalous WebRTC API usage patterns in network traffic, particularly rapid connection establishment and teardown sequences
• Deploy endpoint detection rules to identify heap spray techniques commonly used in browser exploitation
• Analyze Chrome crash dumps for signatures consistent with use-after-free exploitation attempts
• Implement browser version monitoring to identify unpatched Chrome installations across the enterprise

Monitoring Recommendations

• Enable Chrome's built-in Safe Browsing for real-time protection against malicious pages
• Configure centralized browser telemetry to detect unusual crash patterns across endpoints
• Monitor proxy logs for connections to known malicious domains serving browser exploits
• Implement SentinelOne's browser protection capabilities to detect and block exploitation attempts in real-time

How to Mitigate CVE-2025-7657

Immediate Actions Required

• Update Google Chrome to version 138.0.7204.157 or later immediately across all systems
• Enable automatic Chrome updates to ensure timely patch deployment
• Verify Chrome version through chrome://settings/help on all managed endpoints
• Review and restrict WebRTC usage in high-security environments if patches cannot be immediately applied

Patch Information

Google has released Chrome version 138.0.7204.157 which addresses this vulnerability. The fix corrects the memory lifecycle management issue in the WebRTC component, ensuring proper synchronization between object deallocation and reference invalidation. Organizations should deploy this update through their standard browser management infrastructure.

For detailed patch information, see the Google Chrome Update Announcement.

Workarounds

• Disable WebRTC functionality in Chrome using enterprise policies if immediate patching is not feasible
• Implement network-level blocking of WebRTC traffic through firewall rules as a temporary measure
• Use browser isolation solutions to contain potential exploitation attempts
• Restrict browsing to trusted sites only on systems that cannot be immediately patched

# Chrome Enterprise Policy - Disable WebRTC (Windows Registry)
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# Set WebRtcAllowLegacyTLSProtocols = 0
# Or use Chrome Enterprise policy template:
# "WebRtcLocalIpsAllowedUrls": []
# "WebRtcEventLogCollectionAllowed": false