Patchfirst
CVE-2021-21193 KEVPublic exploit High · 8.8 EPSS 10.0%

Google Chromium Blink Use-After-Free Vulnerability

Google · Chromium Blink

Summary

A use-after-free flaw in the Blink rendering engine of Google Chromium (Chrome versions prior to 89.0.4389.90) can lead to heap corruption. A remote attacker can exploit it by getting a victim to open a crafted HTML page, which requires user interaction but no authentication or special configuration.

Official description · NVD

Use after free in Blink in Google Chrome prior to 89.0.4389.90 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Breakdown
68.3 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
2/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited 7 days before it was disclosed. Public exploit code (PoC-in-GitHub) appeared 12 months after disclosure.

  1. First seen exploitedVulnCheck KEV evidence7 days before
  2. Disclosedday 0
  3. Added to CISA KEVEU database agrees+8 mo
  4. Public exploit codePoC-in-GitHub+12 mo

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Drive-by Compromise T1189 Medium
AI mapping from the description · how it is exploited

Malicious web page triggers browser exploitation

allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page
From the official description (NVD) Original (opens in a new tab) ↗

ExecutionTA0002

Command and Scripting Interpreter T1059 Medium
AI mapping from the description · primary impact

Heap corruption enables attacker code execution

Use after free in Blink in Google Chrome
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 98 general rules for its techniques

Rules for this CVE

0 that reference CVE-2021-21193 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

General rules for this CVE’s techniques

These detect the technique in general, not this specific vulnerability.

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

6 links, grouped by NVD tag (5 duplicates merged)
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