CVE-2021-20699: 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

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

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.

Description from the National Vulnerability Database, published by psirt-info@cyber.jp.nec.com

What it means for a small business

If your business uses UN462A, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 1.7%, higher than 76% of CVEs. That’s above average: worth scheduling this week. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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