CVE-2021-4242Public exploitNetwork attack vector

Authenticated command execution via unsanitized sysCmd parameter

Published Nov 30, 2022 · Updated Apr 15, 2025

OS command injection in Sapido BR270n, BRC76n, GR297, and RB1732 allows remote authenticated users to execute shell commands. The ip/syscmd.htm form sends the sysCmd parameter to /boafrm/formSysCmd, which executes the submitted value without command filtering. Access to the router management interface is required; successful requests return command output and permit arbitrary command execution on the appliance.

CVSS severity8.8
High
EPSS probability3.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Sapido BR270n, BRC76n, GR297, and RB1732 allows remote authenticated users to execute shell commands. The ip/syscmd.htm form sends the sysCmd parameter to /boafrm/formSysCmd, which executes the submitted value without command filtering. Access to the router management interface is required; successful requests return command output and permit arbitrary command execution on the appliance.

The record

CVE
CVE-2021-4242
Published
Nov 30, 2022
Updated
Apr 15, 2025
Vendor
Sapido Technology Inc.
Product
RB1732
Classifications
CWE-78, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 30, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Sapido Technology Inc. · RB1732version=n/a
Sapido Technology Inc. · BR270nversion=n/a
Sapido Technology Inc. · BRC76nversion=n/a
Sapido Technology Inc. · GR297version=n/a

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.3VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

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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