External risk intelligence

Google Chrome: Heap Corruption Vulnerability

CVE advisoryKnown Exploit

CVE-2021-21148

A vulnerability in the V8 engine of Google Chrome could allow attackers to exploit heap corruption via a crafted HTML page, potentially affecting systems and data. The risk to organizations is significant, particularly as it is listed on the Known Exploited Vulnerabilities catalog.

4Halo Surface Signal

Out-of-bounds Write

Google Chrome

before 88.0.4324.150323310.0

External exposure likelihood

Halo Surface Signal score for CVE-2021-21148

The vulnerability affects web browsers, which are client-side applications designed to interact with the public internet by rendering remote, untrusted HTML content. While the vulnerability requires a user to navigate to a crafted page, the browser itself is a primary, internet-facing interface commonly used to access external network resources.

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability exists within the V8 JavaScript engine used in Google Chrome. This flaw could permit an attacker to cause heap corruption by presenting a specially crafted HTML page to an organization's systems. The potential business impact includes the compromise of system integrity and unauthorized data access.

  • Vulnerable component: V8 JavaScript engine
  • Core weakness: Heap buffer overflow
  • Main business impact: System compromise and data exposure

Attack Path

How an attacker could exploit the issue

A remote attacker can exploit a heap buffer overflow vulnerability in the V8 JavaScript engine used by Google Chrome. This vulnerability allows for potential heap corruption. Organizations utilizing affected versions of Chrome may be at risk if their systems can be directed to a malicious web page.

  • Exposure on internet-facing systems.
  • Attacker provides crafted HTML page.
  • Triggering heap corruption.

Live Threat

Current exploitation, exposure, and threat context

A vulnerability in a widely used web browser's JavaScript engine presents a significant risk to organizations. Attackers with moderate technical skill could exploit this by luring users to a malicious webpage. Successful exploitation could lead to the compromise of user systems, impacting data confidentiality and integrity.

  • Attackers likely have moderate skill.
  • Requires users to visit a malicious page.
  • High business risk and potential for data loss.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

A heap buffer overflow vulnerability in the V8 engine of Google Chrome allows remote attackers to potentially exploit heap corruption through a crafted HTML page. This could impact organizations by allowing attackers to compromise systems and data if employees access malicious web pages. The High severity rating and inclusion in the Known Exploited Vulnerabilities catalog indicate a significant business risk.

  • Find affected Chrome assets.
  • Reduce exposure or isolate risk.
  • Fix, verify, and monitor.

Frequently asked questions

What is the V8 JavaScript engine in Google Chrome?

The V8 JavaScript engine is a core component of Google Chrome. It's responsible for executing JavaScript code, which is essential for making websites interactive and dynamic. Many other applications and services also use V8.

How does CVE-2021-21148 relate to a heap buffer overflow?

CVE-2021-21148 is a heap buffer overflow vulnerability. This means that a program, in this case, the V8 engine within Google Chrome, attempts to write more data into a memory buffer than it's designed to hold. This can overwrite adjacent memory, leading to unpredictable behavior or corruption.

What are the preconditions for an attacker to exploit this vulnerability?

An attacker needs to present a specially crafted HTML page to the affected user. The vulnerability is not triggered if the user does not interact with such a malicious page.

Who should be concerned about this vulnerability based on Halo Surface Signal?

Organizations should be concerned if their systems, or the systems of their users, interact with the internet. Because web browsers are designed to access external content, this vulnerability is classified as affecting internet-facing systems and therefore poses a relevant risk.

What is a first step for managing this vulnerability?

The first step is to identify all systems running affected versions of Google Chrome. Once identified, organizations should prioritize reducing the potential for exposure or isolating the affected assets until a fix can be applied.

References