Snap Pac S1 FirmwareOperating system · Opto22

CVE-2023-40706

CRITICAL · 9.8 CVSS v3.1 Published 2023-08-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
There is no limit on the number of login attempts in the web server for the SNAP PAC S1 Firmware version R10.3b. This could allow for a brute-force attack on the built-in web server login.

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 · high confidence

The SNAP PAC S1 controller firmware R10.3b contains a web server with no authentication rate limiting or account lockout mechanism. This allows unlimited login attempts, enabling attackers to systematically brute-force credentials against the built-in web server login interface.

MitigationUpdate to a patched firmware version when available. In the interim, restrict network access to the web server using firewall rules or network segmentation, and monitor for brute-force attack patterns.

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
Snap Pac S1 FirmwareOperating system
Affected:= r10.3b

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
High
Integrity
High
Availability
High

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

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 Snap Pac S1 hardware
    Locate the physical controller or check network inventory for device hostname, model name, or MAC vendor OUI (Opto22) to confirm the device is a Snap Pac S1 controller
    Affected if The device is not an Opto22 Snap Pac S1 controller, then this CVE does not apply
  2. Check installed firmware version
    Access the device web interface or use the manufacturer's management software/CLI to retrieve the firmware version. The version string typically appears in the system info or about page
    Affected if The firmware version is exactly r10.3b (R10.3b)
  3. Verify web server is enabled
    Attempt to access the device web interface via HTTP/HTTPS on the expected port (typically 80/443 or configured port). Check device configuration to confirm the web server service is active
    Affected if The web server is disabled or inaccessible, the attack surface may be reduced but the vulnerability still exists in the firmware if later enabled
  4. Check network exposure of web interface
    Review firewall rules, VLAN configuration, or network ACLs to determine if the web login page is reachable from external or untrusted networks
    Affected if The web interface is directly exposed to the internet or untrusted networks, making brute-force attacks feasible
  5. Confirm no rate limiting or account lockout
    Attempt multiple failed login attempts to the web interface (in a test environment). Observe if any account lockout, IP blocking, or rate limiting occurs after repeated failures
    Affected if After multiple failed login attempts, no lockout or rate limiting is triggered - the device allows unlimited attempts

If the device is an Opto22 Snap Pac S1 running firmware R10.3b with its web server enabled and accessible, the vulnerability is present regardless of network exposure.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to a patched firmware version when available. In the interim, restrict network access to the web server using firewall rules or network segmentation, and monitor for brute-force attack patterns.

Fix this in Snap Pac S1 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-40706 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2023-40706 in production — separate from our analysis above.

No notes yet

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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