How severe is CVE-2021-36121?

CVE-2021-36121 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-36121 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36121?

CVE-2021-36121 affects Echobh Sharecare. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-36121?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-36121 published?

CVE-2021-36121 was published on 2021-07-13 and last updated on 2026-06-17.

CVE-2021-36121

CVE-2021-36121 is a high-severity vulnerability in Echobh Sharecare with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-434.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Echobh Sharecare
Published: 2021-07-13
Last modified: 2026-06-17

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).

Frequently asked questions

What is CVE-2021-36121?: 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).
How severe is CVE-2021-36121?: CVE-2021-36121 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-36121 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36121?: CVE-2021-36121 affects Echobh Sharecare. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-36121?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-36121 published?: CVE-2021-36121 was published on 2021-07-13 and last updated on 2026-06-17.

References

https://github.com/atredispartners/advisories/blob/master/ATREDIS-2021-0001.md

Affected products (1)

cpe:2.3:a:echobh:sharecare:8.15.5:*:*:*:*:*:*:*

More vulnerabilities in Echobh Sharecare

CVE-2021-36124 — Critical (CVSS 9.8): An issue was discovered in Echo ShareCare 8.15.5. It does not perform authentication or authorization checks when…
CVE-2021-33578 — Critical (CVSS 9.8): Echo ShareCare 8.15.5 is susceptible to SQL injection vulnerabilities when processing remote input from both…
CVE-2021-36122 — High (CVSS 8.8): An issue was discovered in Echo ShareCare 8.15.5. The UnzipFile feature in Access/EligFeedParse_Sup/UnzipFile_Upd.cfm…
CVE-2021-36123 — Medium (CVSS 6.5): An issue was discovered in Echo ShareCare 8.15.5. The TextReader feature in General/TextReader/TextReader.cfm is…

All CVEs affecting Echobh Sharecare →

Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

CVE-2026-48283 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-48276 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-57700 — Critical (CVSS 10.0): Unrestricted Upload of File with Dangerous Type vulnerability in Daan.Dev OMGF Pro allows Using Malicious Files. This…
CVE-2025-69129 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in WordPress & WooCommerce Scraper Plugin, Import Data from Any Site <= 1.0.7…
CVE-2026-40772 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions.
CVE-2026-40412 — Critical (CVSS 10.0): Unrestricted upload of file with dangerous type in Azure Orbital Spatio allows an unauthorized attacker to execute code…

Browse all CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities →