Ep 801a FirmwareOperating system · Epson

CVE-2023-38556

HIGH · 7.5 CVSS v3.1 Published 2023-08-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
Improper input validation vulnerability in SEIKO EPSON printer Web Config allows a remote attacker to turned off the printer. [Note] Web Config is the software that allows users to check the status and change the settings of SEIKO EPSON printers via a web browser. Web Config is pre-installed in some printers provided by SEIKO EPSON CORPORATION. For the details of the affected product names/model numbers, refer to the information provided by the vendor.

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

Improper input validation in SEIKO EPSON printer Web Config allows remote attackers to send specially crafted requests that cause the printer to turn off, resulting in denial of service. The vulnerability resides in the web-based configuration interface which fails to properly validate user input before processing.

MitigationApply vendor-supplied firmware updates for affected printer models; until patches are available, restrict network access to Web Config or disable it if not needed.

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
Ep 801a FirmwareOperating system
Affected:all versions
Ep 802a FirmwareOperating system
Affected:all versions
Ep 901a FirmwareOperating system
Affected:all versions
Ep 901f FirmwareOperating system
Affected:all versions
Ep 902a FirmwareOperating system
Affected:all versions
Pa Tcu1 FirmwareOperating system
Affected:all versions
Pm T960 FirmwareOperating system
Affected:all versions
Pm T990 FirmwareOperating system
Affected:all versions

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 printer model
    Access the printer's web configuration interface, check the printer's control panel display, or use network discovery tools (such as nmap, Bonjour/mDNS, or SNMP) to identify the exact model number (e.g., Epson EP-801A, EP-901F, PM-T960, etc.)
    Affected if The model matches any of the following: EP-801A, EP-802A, EP-901A, EP-901F, EP-902A, PA-TCU1, PM-T960, PM-T990
  2. Check Web Config status
    Log into the printer's web interface or navigate to the network/settings menu on the printer's control panel to determine whether the Web Config (web-based management interface) feature is enabled
    Affected if Web Config is enabled and accessible over the network (this is the vulnerable component that processes the specially crafted requests)
  3. Verify firmware version
    Check the firmware version through the printer's web configuration interface (typically under Settings, Maintenance, or Information sections) or via the printer's control panel
    Affected if The firmware version is any version (all versions of the listed models are affected per the advisory)

You are affected if your printer model is one of the eight listed models (EP-801A, EP-802A, EP-901A, EP-901F, EP-902A, PA-TCU1, PM-T960, PM-T990) AND Web Config is enabled and accessible on your network.

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

Apply vendor-supplied firmware updates for affected printer models; until patches are available, restrict network access to Web Config or disable it if not needed.

Fix this in Ep 801a Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing3.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,050
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Scan for this in your stack

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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-2023-38556 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