CVE intelligence and bounded remediation

CVE-2021-20699 — Sharp-Nec-Displays Un462A Firmware security vulnerability

Critical CVSS 9.8

Sharp NEC Displays ((UN462A R1.300 and prior to it, UN462VA R1.300 and prior to it, UN492S R1.300 and prior to it, UN492VS R1.300 and prior to it, UN552A R1.300 and prior to it, UN552S R1.300 and prior to it, UN552VS R1.300 and prior to it, UN552 R1.300 and prior to it, UN552V R1.300 and prior to it, UX552S R1.300 and prior to it, UX552 R1.300 and prior to it, V864Q R2.000 and prior to it, C861Q R2.000 and prior to it, P754Q R2.000 and prior to it, V754Q R2.000 and prior to it, C751Q R2.000 and prior to it, V984Q R2.000 and prior to it, C981Q R2.000 and prior to it, P654Q R2.000 and prior to it, V654Q R2.000 and prior to it, C651Q R2.000 and prior to it, V554Q R2.000 and prior to it, P404 R3.200 and prior to it, P484 R3.200 and prior to it, P554 R3.200 and prior to it, V404 R3.200 and prior to it, V484 R3.200 and prior to it, V554 R3.200 and prior to it, V404-T R3.200 and prior to it, V484-T R3.200 and prior to it, V554-T R3.200 and prior to it, C501 R2.000 and prior to it, C551 R2.000 and prior to it, C431 R2.000 and prior to it) allows an attacker a buffer overflow and to execute remote code by sending long parameters that contains specific characters in http request.

Severity
Critical
CVSS
9.8 (3.1)
Published
2021-06-07
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-77, CWE-120

Affected products

  • sharp-nec-displays / un462a_firmware
  • sharp-nec-displays / un462va_firmware
  • sharp-nec-displays / un492s_firmware
  • sharp-nec-displays / un492vs_firmware
  • sharp-nec-displays / un552a_firmware
  • sharp-nec-displays / un552s_firmware

Showing 6 representative product identities from 34 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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