CVE-2023-38556Network attack vector

Unauthenticated printer shutdown via improperly validated URL

Published Aug 2, 2023 · Updated Oct 21, 2024

Improper input validation in Seiko Epson Web Config allows remote attackers to shut down affected printers through a web request. The embedded interface processes a vendor-identified specific URL without adequate input validation and invokes the printer's power-off behavior; Epson has not disclosed the URL or parsing defect. No authentication or user interaction is required, and the reported consequence is a printer shutdown without confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in Seiko Epson Web Config allows remote attackers to shut down affected printers through a web request. The embedded interface processes a vendor-identified specific URL without adequate input validation and invokes the printer's power-off behavior; Epson has not disclosed the URL or parsing defect. No authentication or user interaction is required, and the reported consequence is a printer shutdown without confidentiality or integrity impact.

The record

CVE
CVE-2023-38556
Published
Aug 2, 2023
Updated
Oct 21, 2024
Vendor
Seiko Epson Corporation
Product
Web Config
Classifications
CWE-20, T1529
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Seiko Epson Corporation · Web Configversion=unspecified

Published CVSS scores

7.8JPCERT/CCAV:N/AC:L/Au:N/C:N/I:N/A:C
7.5JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1529System Shutdown/Reboot

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo