CVE-2021-20698Network attack vector

Unauthenticated root code execution via cgictrl injection

Published Jun 7, 2021 · Updated Dec 8, 2025

Command injection in Sharp NEC public display firmware allows remote attackers to execute arbitrary code as root through crafted HTTP requests. The cgictrl binary in the administrative web console fails to neutralize special characters in request parameters before command execution. No authentication or user interaction is required; network access to an affected display is enough to take complete control of the device.

CVSS severity9.8
Critical
EPSS probability1.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Sharp NEC public display firmware allows remote attackers to execute arbitrary code as root through crafted HTTP requests. The cgictrl binary in the administrative web console fails to neutralize special characters in request parameters before command execution. No authentication or user interaction is required; network access to an affected display is enough to take complete control of the device.

The record

CVE
CVE-2021-20698
Published
Jun 7, 2021
Updated
Dec 8, 2025
Vendor
Sharp Display Solutions, Ltd.
Product
V554Q
Classifications
CWE-77, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Dec 8, 2025Record 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=0 <=R2.000

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sharp Display Solutions, Ltd. · V554Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · UX552version=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync P554version=0 <=R3.201
Sharp Display Solutions, Ltd. · NEC MultiSync C751Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync UN462VAversion=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync P654Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · V404version=0 <=R3.201
Sharp Display Solutions, Ltd. · UN552VSversion=0 <=R1.300
Sharp Display Solutions, Ltd. · V984Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync C651Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · UX552Sversion=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync P754Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync UN552Aversion=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync UN492Sversion=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync UN552version=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync UN492VSversion=0 <=R1.300
Sharp Display Solutions, Ltd. · V484version=0 <=R3.201
Sharp Display Solutions, Ltd. · NEC MultiSync C431version=0 <=R2.000
Sharp Display Solutions, Ltd. · V864Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync P484version=0 <=R3.201
Sharp Display Solutions, Ltd. · V554version=0 <=R3.201
Sharp Display Solutions, Ltd. · V754Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync UN462Aversion=0 <=R1.300
Sharp Display Solutions, Ltd. · V484-Tversion=0 <=R3.201
Sharp Display Solutions, Ltd. · NEC MultiSync P404version=0 <=R3.201
Sharp Display Solutions, Ltd. · NEC MultiSync C861Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync C501version=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync C981Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · NEC MultiSync UN552Vversion=0 <=R1.300
Sharp Display Solutions, Ltd. · NEC MultiSync UN552Sversion=0 <=R1.300
Sharp Display Solutions, Ltd. · V654Qversion=0 <=R2.000
Sharp Display Solutions, Ltd. · V554-Tversion=0 <=R3.201
Sharp Display Solutions, Ltd. · V404-Tversion=0 <=R3.201
Sharp Display Solutions, Ltd. · NEC MultiSync C551version=0 <=R2.000

Published CVSS scores

10.0NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1190Exploit Public-Facing Application

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

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Your stack

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