CVE-2021-34992

8.8 highEPSS 4.3%

High (8.8) in orckestra c1 cms. EPSS 4.3% chance of exploitation in the next 30 days.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Orckestra C1 CMS 6.10. Authentication is required to exploit this vulnerability. The specific flaw exists within Composite.dll. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-14740.

Severity

CVSS 3.1

8.8 high

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

EPSS: 4.3% chance of exploitation in the next 30 days; higher than 91% of CVEs (scores of 2026-10-31)
CWE: CWE-502
Published: 2021-11-15
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

orckestra:c1_cms

References

https://github.com/Orckestra/C1-CMS-Foundation/releases/tag/v6.11
https://www.zerodayinitiative.com/advisories/ZDI-21-1304/
https://github.com/Orckestra/C1-CMS-Foundation/releases/tag/v6.11
https://www.zerodayinitiative.com/advisories/ZDI-21-1304/

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