9.6

CVE-2021-30633: Google Chromium Indexed DB API Use-After-Free Vulnerability

KEV
Analyzed
AliasesUBUNTU-CVE-2021-30633DEBIAN-CVE-2021-30633ALPINE-CVE-2021-30633
Published 08-10-2021Last modified 21-10-2025

Vulnerability summary

CVE-2021-30633 is a critical (CVSS 9.6) Use After Free vulnerability in Google Chromium Indexed DB API. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 33.18% chance of exploitation in the next 30 days, higher than 98.3% of scored vulnerabilities.

Priority
Act nowlisted as exploited

Listed as exploited by CISA (03-11-2021)

Source freshness unavailable

How is this decided?
CVSS score
9.6/10
010
Critical · v3.1 (CVE.org)
EPSS score
33.18%
0%100%
High · 0.00 pp in 30 days
KEVExploited in the wildCritical · listed in 1 catalog
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 9 · Related 8

Timeline

  1. 08-10-2021
    PublishedVulnerability first disclosed.
  2. 03-11-2021
    Added to CISA KEVExploitedGoogle Chromium Indexed DB API Use-After-Free Vulnerability
  3. 17-11-2021
    CISA remediation dueDeadline passedApply updates per vendor instructions.
  4. 21-10-2025
    Last modifiedVulnerability information updated.

Description

Use after free in Indexed DB API in Google Chrome prior to 93.0.4577.82 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.

CVSS metrics

6 scores · 5 sources · 2 versions

EPSS trend

Probability

33.18%

Chance of exploitation in the next 30 days

Percentile

98%

Versus all other CVEs

30-day change

No change 0.00 pp

From 33.18% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
03-11-2021
Federal due date
17-11-2021
ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

CISA required action

Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2021-30633

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine2 products
  • chromium< 93.0.4577.82-r0
  • qt5-qtwebengine< 5.15.3_git20211006-r0
Debian1 product
  • chromium< 93.0.4577.82-1
Fedoraproject1 product
Google1 product
  • chrome≥ unspecified, < 93.0.4577.82 | < 93.0.4577.82
Ubuntu1 product
  • chromium-browser< 94.0.4606.71-0ubuntu0.18.04.1

5 vendors · 6 products

References

10 links