CVE-2021-30633

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2021-11-17.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

33.18% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 98.2% of scored records. A rank, not a probability.

NVD base score

9.6 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-10-08 20:50Z5 YR AGO

Last updated

2025-10-21 23:25Z1 YR AGO

Reserved

2021-04-13

Assigning CNA

Chrome

Record state

PUBLISHED

Severity

Critical (CVSS 9.6)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Weaknesses

• CWE-416Use After FreeVariant

Data version

5.1

Document digest

326589902b3adc657ecd70dbd3f1bd4b2dbcd00b6bcb9366a519b815ce3ea65b

• chromereleases.googleblog.comhttps://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop.htmlx_refsource_MISC
• crbug.comhttps://crbug.com/1247766x_refsource_MISC
• lists.fedoraproject.orgFEDORA-2021-ab09a05562https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4DDW7HAHTS3SDVXBQUY4SURELO5D4X7R/vendor-advisoryx_refsource_FEDORA
• lists.fedoraproject.orgFEDORA-2021-591b3a2af0https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PM7MOYYHJSWLIFZ4TPJTD7MSA3HSSLV2/vendor-advisoryx_refsource_FEDORA
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30633government-resource