CVE-2025-2783: Google Chrome RCE Vulnerability

CVE-2025-2783 Overview

CVE-2025-2783 is a sandbox escape vulnerability in the Mojo inter-process communication (IPC) layer of Google Chrome on Windows. The flaw stems from an incorrect handle being provided under unspecified circumstances, allowing a remote attacker to break out of the Chrome renderer sandbox using a malicious file. Google patched the issue in Chrome 134.0.6998.177 for the Windows desktop stable channel. CISA added the vulnerability to its Known Exploited Vulnerabilities catalog after evidence emerged of active exploitation against Windows users. The EPSS score sits at 46.86% (97.7th percentile), reflecting a high probability of continued exploitation attempts.

Critical Impact

Attackers can escape the Chrome sandbox on Windows hosts and execute code outside the renderer process by tricking a user into opening crafted content.

Affected Products

• Google Chrome on Windows prior to 134.0.6998.177
• Chromium-based browsers sharing the same Mojo IPC code path on Windows
• Microsoft Windows hosts running vulnerable Chrome builds

Discovery Timeline

• 2025-03-26 - CVE-2025-2783 published to NVD
• 2025-10-24 - Last updated in NVD database

Technical Details for CVE-2025-2783

Vulnerability Analysis

The vulnerability resides in Mojo, the IPC framework Chrome uses to mediate communication between sandboxed renderer processes and higher-privileged broker processes. On Windows, Mojo passes operating system handles between processes during channel setup and message exchange. The defect causes an incorrect handle to be supplied in undisclosed conditions, breaking the trust boundary that the sandbox relies upon.

Exploitation lets a remote attacker pivot from a compromised renderer to code execution outside the sandbox. Combined with a renderer-side bug or a malicious file delivered through the browser, the issue produces a full sandbox escape on Windows. Google withheld further technical detail to protect users while patches rolled out, and the Chromium issue tracker entry remains restricted.

Root Cause

The root cause is improper handle handling within Mojo on Windows. A handle intended for one process or scope is delivered to another, granting it access it should not possess. This breaks the principle that the broker process must validate and confine the resources it exposes to lower-privileged renderers.

Attack Vector

The attack requires user interaction. A victim must open or interact with a malicious file or web resource processed by Chrome. Once the attacker controls execution within the renderer, the Mojo handle confusion allows escape into the broker context, where Chrome operates with the user's full privileges on Windows. The bug has been observed in targeted attacks before patching.

No verified public exploit code is mirrored in this article. Refer to the Chromium Issue Tracker and the Google Chrome Update Blog for vendor information.

Detection Methods for CVE-2025-2783

Indicators of Compromise

• Chrome renderer processes spawning unexpected child processes such as cmd.exe, powershell.exe, or rundll32.exe outside normal browser workflows.
• Unsigned or unusual DLLs loaded into chrome.exe broker or utility processes.
• Outbound network connections from Chrome utility processes to attacker-controlled infrastructure shortly after a user opens a suspicious link or file.

Detection Strategies

• Hunt for Chrome version strings older than 134.0.6998.177 on Windows endpoints through software inventory queries.
• Alert on Chrome process lineage anomalies where renderer or utility processes create new executables on disk and then launch them.
• Correlate browser-initiated file writes in user-writable directories (%TEMP%, %APPDATA%) with subsequent process creation events.

Monitoring Recommendations

• Forward Chrome process telemetry, including command-line arguments and parent-child relationships, into a centralized analytics platform for behavioral baselining.
• Monitor Mojo-related crash dumps and Chrome stability telemetry that may indicate exploitation attempts.
• Track inbound phishing campaigns delivering links or attachments that target Chrome users on Windows.

How to Mitigate CVE-2025-2783

Immediate Actions Required

• Update Google Chrome on Windows to 134.0.6998.177 or later across all managed endpoints.
• Force-restart Chrome after deployment so the patched binaries replace running processes.
• Audit Chromium-based browsers in the environment, including Microsoft Edge and Brave, and apply vendor updates that incorporate the Mojo fix.

Patch Information

Google released the fix in the stable channel update for desktop on Windows at version 134.0.6998.177. The advisory and update notes are available in the Google Chrome Update Blog. CISA tracks remediation deadlines for federal agencies in the CISA Known Exploited Vulnerabilities Catalog.

Workarounds

• Restrict Chrome usage on Windows hosts that cannot be patched immediately by routing browsing through hardened alternatives or remote browser isolation.
• Block delivery of suspicious file types and links at the email gateway and web proxy until patching is verified.
• Apply Windows application control policies that prevent Chrome processes from spawning script interpreters and arbitrary child executables.

# Verify deployed Chrome version on Windows endpoints (PowerShell)
(Get-Item "$env:ProgramFiles\Google\Chrome\Application\chrome.exe").VersionInfo.ProductVersion