dbcve.org
Single ConnectApplication · Krontech

CVE-2021-44794

MEDIUM · 5.3 CVSS v3.1 Published 2022-01-27
Fix available
A fix is available. Upgrade to 2.16 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Single Connect does not perform an authorization check when using the "sc-diagnostic-ui" module. A remote attacker could exploit this vulnerability to access the device information page. The exploitation of this vulnerability might allow a remote attacker to obtain sensitive information.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The Single Connect sc-diagnostic-ui module lacks an authorization check, allowing unauthenticated remote attackers to access the device information page and potentially obtain sensitive system information. This is a broken access control vulnerability exploitable via direct API or web request to the diagnostic interface.

MitigationImplement proper authentication and authorization enforcement on the sc-diagnostic-ui module to ensure only authorized users can access device information pages. This typically involves adding session validation and role-based access control (RBAC) checks before rendering sensitive data.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Single ConnectApplication
Affected:< 2.16

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Single Connect product
    Check the system documentation, web interface footer, or use command-line tools like 'cat /etc/version' or 'systemctl status' to confirm the product is Krontech Single Connect.
    Affected if The system is NOT Krontech Single Connect, then this CVE does not apply.
  2. Check the installed version
    Locate the Single Connect version number in the administrative web UI (typically in Settings > About or System Information), or run: 'grep -r "version" /opt/single-connect' or check the package manager if installed via dpkg/rpm.
    Affected if The installed version is lower than 2.16 (e.g., 2.15.x, 2.14.x, etc.), indicating the system falls within the vulnerable version range.
  3. Verify sc-diagnostic-ui module accessibility
    Attempt to access the diagnostic interface directly via browser or curl: 'curl http://<device-ip>/sc-diagnostic-ui/' or 'curl http://<device-ip>/api/diagnostic/device-info' without providing any credentials.
    Affected if The diagnostic page loads and returns system information (device details, configuration, or sensitive data) without requiring login credentials, confirming the broken access control.
  4. Confirm authentication enforcement on diagnostic endpoint
    Check the web server configuration (e.g., nginx/apache config in /etc/nginx/conf.d/ or /etc/httpd/conf.d/) or application configuration files for session validation or RBAC middleware on the /sc-diagnostic-ui routes.
    Affected if No authentication check (session cookie validation, login redirect, or 401/403 response) is configured for the sc-diagnostic-ui endpoints, meaning the vulnerability is present.

The environment is affected if the system is Krontech Single Connect with version lower than 2.16 AND the sc-diagnostic-ui module is accessible without authentication credentials.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.16 or later
Fixed in 2.16
Interim mitigation

Implement proper authentication and authorization enforcement on the sc-diagnostic-ui module to ensure only authorized users can access device information pages. This typically involves adding session validation and role-based access control (RBAC) checks before rendering sensitive data.

Recommended fix Moderate confidence

Single Connect version 2.16

  1. Upgrade Single Connect to version 2.16 or later to address the missing authorization check in the sc-diagnostic-ui module
  2. After upgrade, verify that the sc-diagnostic-ui module now requires proper authentication/authorization
  3. Confirm that unauthenticated users can no longer access the device information page
Caveat Review release notes for version 2.16 for any configuration or compatibility changes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Single Connect Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-44794 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data