CVE-2023-0129: Google Chrome Buffer Overflow Vulnerability

CVE-2023-0129 Overview

CVE-2023-0129 is a heap buffer overflow vulnerability in the Network Service component of Google Chrome prior to version 109.0.5414.74. The flaw allows an attacker who convinces a user to install a malicious extension to trigger heap corruption through a crafted HTML page and specific interactions. Google rates the Chromium security severity as High. The vulnerability is classified under CWE-787 (Out-of-bounds Write) and impacts confidentiality, integrity, and availability when exploited successfully.

Critical Impact
Successful exploitation can lead to heap corruption in the Network Service process, enabling potential arbitrary code execution within the browser's sandboxed network component.

Affected Products

Google Chrome versions prior to 109.0.5414.74
Chromium-based browsers using the affected Network Service component
Gentoo Linux Chrome packages (addressed in GLSA 202305-10 and GLSA 202311-11)

Discovery Timeline

2023-01-10 - CVE-2023-0129 published to the National Vulnerability Database (NVD)
2023-01-10 - Google releases Chrome 109.0.5414.74 via the Stable Channel Update for Desktop
2025-05-05 - Last updated in the NVD database

Technical Details for CVE-2023-0129

Vulnerability Analysis

The vulnerability resides in the Network Service component of Google Chrome, which handles network operations such as HTTP requests, sockets, and resource loading. A heap buffer overflow occurs when the service writes data beyond the allocated boundary of a heap buffer. Exploitation requires user interaction in the form of installing a malicious browser extension. Once the extension is loaded, an attacker delivers a crafted HTML page and triggers specific interactions to corrupt heap memory. Heap corruption in this privileged browser process can lead to arbitrary code execution, sandbox escape attempts, or denial of service.

Root Cause

The root cause is improper bounds checking when the Network Service writes data to a heap-allocated buffer. This out-of-bounds write condition aligns with [CWE-787] and reflects insufficient input validation on attacker-influenced data flowing through the network stack. The malicious extension supplies the attack surface required to reach the vulnerable code path that ordinary web content cannot directly invoke.

Attack Vector

The attack vector is network-based with required user interaction. An attacker must first persuade the victim to install a malicious Chrome extension. The extension then loads a crafted HTML page and performs specific interactions that exercise the vulnerable Network Service code path. Because the extension already operates with elevated browser privileges compared to standard web content, it provides a reliable trigger for the heap corruption primitive.

No verified public proof-of-concept code or exploit is available for this vulnerability. Refer to Chromium Bug Report #1382033 for additional technical context once access restrictions are lifted.

Detection Methods for CVE-2023-0129

Indicators of Compromise

Unexpected or unsigned Chrome extensions installed from outside the Chrome Web Store
Crashes or anomalous termination of the Chrome Network Service process (utility process with --utility-sub-type=network.mojom.NetworkService)
Outbound connections from Chrome to unknown domains shortly after extension installation

Detection Strategies

Inventory installed Chrome extensions across the fleet and compare against an approved allowlist
Monitor Chrome version telemetry to identify endpoints running builds older than 109.0.5414.74
Review crash reports and Windows Error Reporting or macOS CrashReporter logs for Network Service exceptions

Monitoring Recommendations

Enable centralized logging of Chrome enterprise policies, including ExtensionInstallBlocklist and ExtensionInstallAllowlist events
Alert on new extension installations originating from developer mode or sideloaded .crx files
Correlate browser crash events with subsequent suspicious process activity using endpoint telemetry

How to Mitigate CVE-2023-0129

Immediate Actions Required

Update Google Chrome to version 109.0.5414.74 or later on all managed endpoints
Audit installed extensions and remove any that are unapproved, unsigned, or sourced outside the Chrome Web Store
Enforce extension allowlisting through Chrome enterprise policy to block installation of unvetted extensions

Patch Information

Google addressed CVE-2023-0129 in the Chrome Stable Channel release 109.0.5414.74 announced on January 10, 2023. See the Google Chrome Update Blog for the full advisory. Gentoo Linux published patched packages via GLSA 202305-10 and GLSA 202311-11.

Workarounds

Restrict extension installation to a vetted allowlist using the ExtensionInstallAllowlist Chrome policy
Block sideloading by disabling developer mode through the DeveloperToolsAvailability policy on managed devices
Educate users to install extensions only from the official Chrome Web Store and to avoid unsolicited extension prompts

bash

# Example Chrome enterprise policy (Linux JSON managed policy)
# /etc/opt/chrome/policies/managed/extension_controls.json
{
  "ExtensionInstallBlocklist": ["*"],
  "ExtensionInstallAllowlist": [
    "approved-extension-id-1",
    "approved-extension-id-2"
  ],
  "DeveloperToolsAvailability": 2
}