CVE-2021-42237

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2022-03-25. Federal remediation due 2022-04-15.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• 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

97.90% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 99.9% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Analyzed. NVD last modified this record on 2026-07-09.

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

2021-11-05 09:51Z4 YR AGO

Last updated

2026-07-09 00:15Z1 MO AGO

Reserved

2021-10-11

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

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

Weaknesses

• CWE-502Deserialization of Untrusted DataBase

Data version

5.2

Document digest

9a876a9d36700c9c7c825a42a46e19f3439cf7e9dcd9e8ba8b91ff956d837e9b

• support.sitecore.comhttps://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB1000776
• blog.assetnote.iohttps://blog.assetnote.io/2021/11/02/sitecore-rce/
• packetstormsecurity.comhttp://packetstormsecurity.com/files/164988/Sitecore-Experience-Platform-XP-Remote-Code-Execution.html
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42237government-resource