CVE-2021-42237
KEVRansomware UseSitecore XP Remote Command Execution Vulnerability
Description
Sitcore XP contains an insecure deserialization vulnerability which can allow for remote code execution.
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.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HPublishedNov 5, 2021
Last modifiedJul 9, 2026
Added to KEVMar 25, 2022
Remediation dueApr 15, 2022
References
- packetstormsecurity.com/files/164988/Sitecore-Experience-Platform-XP-Remote-Code-Execution.htmlThird Party AdvisoryVDB Entry
- blog.assetnote.io/2021/11/02/sitecore-rce/ExploitThird Party Advisory
- support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB1000776Vendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42237US Government Resource
0 recent articles mention this CVE
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Risk assessment · Critical
Actively exploited and used by ransomware crews. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1655 days
- Ransomware
- Used in known ransomware campaigns
- CVSS
- 9.8 CRITICAL
- EPSS (30-day exploit probability)
- 97.6% · top 1% of all CVEs
- Weakness
- CWE-502
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
- 5.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.