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ExploitedIn CISA KEV

CVE-2021-42237

Exploitation confirmed. First attested on 2022-03-25 by CISA-ADP, CISA KEV, GCVE · kevintel, GCVE · shadowserver.

  • Published2021-11-05
  • WeaknessCWE-502

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine. No authentication or special configuration is required to exploit this vulnerability.

Timeline

dates in UTC
  1. 2021-11-0510:15CVE publishedNVD
  2. 2022-03-25Added to the CISA KEV catalogCISA KEV
  3. 2022-03-25Listed as exploited by GCVEGCVE
  4. 2022-03-25Exploitation first reportedCISA KEV
  5. 2025-02-0314:09SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-42237?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-42237?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Sitecore experience platform
BranchAffectedFixed in
7.5= 7.5no fix published
8.0= 8.0no fix published
8.1= 8.1no fix published
8.2= 8.2no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. CISA’s required action: Apply updates per vendor instructions.due 2022-04-15

Advisories and patches

Detection

read 2026-11-02 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
3 repositories, unverifiedItsIgnacioPortal/CVE-2021-42237vesperp/CVE-2021-42237-SiteCore-XPcrankyyash/SiteCore-RCE-Detection
PoC-in-GitHub
Metasploit modules
1 moduleexploit/windows/http/sitecore_xp_cve_2021_42237rank: excellentModule metadata: Metasploit Framework, © Rapid7, Inc., BSD-3-Clause.
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2022-03-25
Patch Due Date
2022-04-15
Ransomware Use
Known
Required Action
Apply updates per vendor instructions.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2021-11-05
Last Modified
2026-07-09
NVD status
Analyzed
GitHub Advisory
GHSA-j3x5-fr4h-9v7v

Frequently asked questions

What is CVE-2021-42237?

Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine. No authentication or special configuration is required to exploit this vulnerability.

Is CVE-2021-42237 actively exploited?

Yes. CVE-2021-42237 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-04-15.

What is the CVSS score for CVE-2021-42237?

CVE-2021-42237 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record