Is CVE-2021-36121 actively exploited?

No active exploitation of CVE-2021-36121 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-36121 be exploited remotely?

Yes. CVE-2021-36121 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-36121?

CVE-2021-36121 has a CVSS score of 8.8 (HIGH).

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HIGH

CVE-2021-36121

CWE-434Published: July 13, 2021· Updated: Jun 17, 2026

8.8

CVSS v3.1

Official Description

An issue was discovered in Echo ShareCare 8.15.5. The file-upload feature in Access/DownloadFeed_Mnt/FileUpload_Upd.cfm is susceptible to an unrestricted upload vulnerability via the name1 parameter, when processing remote input from an authenticated user, leading to the ability for arbitrary files to be written to arbitrary filesystem locations via ../ Directory Traversal on the Z: drive (a hard-coded drive letter where ShareCare application files reside) and remote code execution as the ShareCare service user (NT AUTHORITY\SYSTEM).

NVD Source

Technical Analysis

CVE-2021-36121 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.