Security readout for executives and security teams
Plain-English summary
This CVE describes root-level command execution on specific TerraMaster NAS models running TOS 4.2.X. If exposed, an attacker could potentially take full control of the appliance. The source bundle does not confirm active exploitation, authentication requirements, CVSS score, or a vendor-fixed version.
Executive priority
Prioritize exposed TerraMaster NAS devices because successful exploitation could mean root-level appliance compromise. If devices are internal-only, still remediate promptly due to public vulnerability details and incomplete source evidence about authentication requirements.
Technical view
CVE-2021-45840 affects TerraMaster F4-210 and F2-210 TOS 4.2.X, specifically build 4.2.15-2107141517. Crafted input to /tos/index.php?app/app_start_stop can execute arbitrary commands as root. Public details exist, but the bundle lacks CVSS, CWE, authentication context, and remediation specifics.
Likely exposure
Exposure is limited to TerraMaster F4-210 and F2-210 devices running the named TOS 4.2.X build. Risk rises sharply if the TOS web interface is reachable from the internet or untrusted networks. The bundle does not establish whether authentication is required.
Exploitation context
A public technical write-up is referenced by the CVE record. CISA KEV status is false in the bundle, and no cited source states active exploitation. Treat public detail as increasing risk, but do not assume exploitation in your environment without evidence.
Researcher notes
Key gaps are CVSS, CWE, authentication requirement, and official fix information. The CVE record identifies the affected route and root command execution impact, but validation should avoid intrusive testing unless explicitly authorized and controlled.
Mitigation direction
- Check TerraMaster guidance for a fixed TOS release before upgrading.
- Remove TOS management interfaces from internet exposure.
- Restrict NAS administration to trusted networks or VPN access.
- Review administrative accounts and reset credentials if compromise is suspected.
- Monitor for suspicious access to the affected TOS endpoint.
Validation and detection
- Inventory TerraMaster F4-210 and F2-210 devices.
- Confirm TOS version and build number on each device.
- Check whether the TOS web interface is externally reachable.
- Review web and system logs for suspicious endpoint access.
- Verify remediation by confirming the vendor-supported fixed build.
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.
CVE-2021-45840 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://thatsn0tmy.site/posts/2021/12/how-to-summon-rces/CVE 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.