CVE-2025-0999: Google Chrome Buffer Overflow Vulnerability

CVE-2025-0999 Overview

CVE-2025-0999 is a heap buffer overflow vulnerability affecting the V8 JavaScript engine in Google Chrome prior to version 133.0.6943.126. This memory corruption vulnerability allows a remote attacker to potentially exploit heap corruption through a crafted HTML page, enabling arbitrary code execution in the context of the browser process.

Critical Impact

Remote attackers can exploit this heap buffer overflow in Chrome's V8 engine to execute arbitrary code, potentially compromising user systems through malicious web pages.

Affected Products

• Google Chrome versions prior to 133.0.6943.126
• Chromium-based browsers using vulnerable V8 engine versions
• All desktop platforms running affected Chrome versions (Windows, macOS, Linux)

Discovery Timeline

• 2025-02-19 - CVE-2025-0999 published to NVD
• 2025-04-07 - Last updated in NVD database

Technical Details for CVE-2025-0999

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), a critical memory corruption issue within the V8 JavaScript engine. V8 is the core JavaScript and WebAssembly engine that powers Google Chrome and is responsible for parsing, compiling, and executing JavaScript code. The heap buffer overflow occurs when the engine improperly handles memory boundaries during certain JavaScript operations, allowing memory adjacent to allocated buffers to be overwritten.

The attack requires user interaction—specifically, a victim must navigate to a malicious webpage containing specially crafted HTML and JavaScript designed to trigger the vulnerable code path. Once triggered, the heap corruption can be leveraged to gain control over program execution, potentially allowing attackers to execute arbitrary code with the privileges of the browser process.

Root Cause

The root cause of CVE-2025-0999 lies in improper bounds checking within V8's memory management routines. When processing certain JavaScript constructs, the engine fails to adequately validate buffer sizes before writing data, resulting in a classic heap buffer overflow condition. This allows attackers to write beyond allocated memory boundaries, corrupting adjacent heap structures and potentially overwriting critical data such as function pointers or object metadata.

Attack Vector

The attack vector for this vulnerability is network-based, requiring a victim to visit a malicious website. An attacker would craft a webpage containing specially designed HTML and JavaScript that triggers the heap overflow in V8. The exploitation chain typically involves:

1. Luring a victim to a malicious or compromised website
2. The webpage loads JavaScript that triggers the vulnerable code path in V8
3. Heap corruption occurs, allowing the attacker to manipulate memory layout
4. The attacker leverages the corruption to achieve code execution or sandbox escape

For detailed technical information about this vulnerability, refer to the Chromium Issue #394350433 and the Google Chrome Stable Update announcement.

Detection Methods for CVE-2025-0999

Indicators of Compromise

• Unexpected Chrome browser crashes or instability, particularly when visiting unknown websites
• Abnormal memory consumption patterns in Chrome or V8 engine processes
• Suspicious JavaScript execution patterns in browser logs
• Chrome process spawning unexpected child processes or network connections

Detection Strategies

• Monitor Chrome version across enterprise endpoints to identify systems running versions prior to 133.0.6943.126
• Deploy endpoint detection solutions capable of identifying heap spray techniques and memory corruption exploitation
• Implement browser isolation technologies to contain potential exploitation attempts
• Utilize network security tools to detect and block known malicious domains hosting exploit code

Monitoring Recommendations

• Enable enhanced logging for Chrome browser events and crash reports
• Monitor for unusual V8 engine behavior through Chrome's internal crash reporting
• Track browser process behavior for signs of sandbox escape attempts
• Implement real-time vulnerability scanning to identify unpatched Chrome installations

How to Mitigate CVE-2025-0999

Immediate Actions Required

• Update Google Chrome to version 133.0.6943.126 or later immediately
• Enable automatic updates for Chrome to ensure timely security patch deployment
• Review and update Chromium-based browsers (Edge, Brave, Opera) that may share the vulnerable V8 engine
• Consider implementing browser isolation for high-risk users until patches are deployed

Patch Information

Google has addressed this vulnerability in Chrome version 133.0.6943.126. The fix was announced in the Google Chrome Stable Update published on February 18, 2025. Organizations should prioritize updating all Chrome installations to this version or later. Additional technical details can be found in the Chromium Issue #394350433.

Workarounds

• Enable Site Isolation in Chrome (chrome://flags/#enable-site-per-process) to limit cross-site exploitation potential
• Consider using content security policies to restrict JavaScript execution from untrusted sources
• Deploy web filtering solutions to block access to known malicious domains
• Disable JavaScript on untrusted sites using browser extensions if updating is not immediately possible

# Verify Chrome version on Linux/macOS
google-chrome --version
# Expected output: Google Chrome 133.0.6943.126 or later

# Force Chrome update check
# Navigate to chrome://settings/help in browser
# Or use enterprise deployment tools for managed environments