Security readout for executives and security teams
Plain-English summary
Echo ShareCare 8.15.5 has an authenticated file-upload flaw that can let a logged-in user place arbitrary files in application locations and achieve code execution as NT AUTHORITY\SYSTEM. That is a severe compromise path for any affected deployment.
Executive priority
Treat this as urgent for any confirmed ShareCare 8.15.5 deployment. Authenticated SYSTEM-level code execution can support full application server compromise, data exposure, service disruption, and lateral movement.
Technical view
The vulnerable endpoint is Access/DownloadFeed_Mnt/FileUpload_Upd.cfm. The name1 parameter can be abused during upload processing to traverse directories on the hard-coded Z: drive, where ShareCare application files reside, allowing arbitrary filesystem writes and remote code execution as the ShareCare service user.
Likely exposure
Exposure appears limited to organizations running Echo ShareCare 8.15.5 where authenticated users can reach the file-upload feature. The source bundle does not identify other affected versions, CPEs, hosting models, or default exposure conditions.
Exploitation context
The provided sources describe exploitation by an authenticated user, not unauthenticated internet-scale exploitation. CISA KEV is false in the bundle, and no cited source here supports active exploitation in the wild.
Researcher notes
The CVE data lacks CVSS, CWE, CPE, and patch details. The strongest technical evidence is the referenced Atredis advisory and CVE description. Do not assume broader version impact or active exploitation without additional vendor or threat intelligence confirmation.
Mitigation direction
- Check Echo ShareCare vendor guidance for fixed versions or supported remediation.
- Restrict access to the affected upload feature to trusted users only.
- Disable or isolate the upload workflow if business operations allow.
- Monitor ShareCare application paths for unexpected file creation or modification.
- Review service account privileges and reduce unnecessary filesystem write access.
Validation and detection
- Inventory systems for Echo ShareCare 8.15.5.
- Confirm who can authenticate to the upload functionality.
- Review application and upload logs for unusual filenames or write locations.
- Inspect ShareCare application directories for unexpected files.
- Verify vendor remediation or compensating controls are documented and active.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-36121 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/atredispartners/advisories/blob/master/ATREDIS-2021-0001.mdCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.