Is CVE-2021-21148 actively exploited?

Yes. CVE-2021-21148 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-21148 be exploited remotely?

The attack vector of CVE-2021-21148 has not been classified yet.

What is the CVSS score of CVE-2021-21148?

CVE-2021-21148 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-21148

HIGHCISA KEVIN THE WILD

CVE-2021-21148

Published: November 3, 2021

EPSS:24.87%probability of exploitation in 30 daysPercentile:96.0th

Official Description

Google Chromium V8 Engine contains a heap buffer overflow vulnerability that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.

NVD Source

CISA KEV Advisory

Google Chromium V8 Heap Buffer Overflow Vulnerability

Added to KEV: 2021-11-03Federal patch deadline: 2021-11-17

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

This high-severity heap buffer overflow in the Google Chromium V8 Engine allows a remote attacker to corrupt memory by tricking a user into visiting a specially crafted HTML page. This is a critical flaw with confirmed exploitation in the wild, making it an urgent concern for systems using Chromium-based browsers. The EPSS score of 0.24871 indicates a significant likelihood of exploitation.

Active exploitation of this vulnerability has been observed in the wild, and it is listed in CISA's KEV catalog. Since it can be triggered remotely via a crafted HTML page, it is remotely exploitable.

Recommended Action

Ensure all Chromium-based web browsers, such as Google Chrome, Microsoft Edge, and Opera, are updated to the latest secure versions. Regular patching of web browsers is crucial to prevent exploitation of such client-side vulnerabilities.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-21148 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-21148 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.