CVE-2021-43711Public exploitNetwork attack vector

Unauthenticated command execution via controllable parameter names

Published Jan 4, 2022 · Updated Aug 4, 2024

Command injection in TOTOLINK EX200 firmware 4.0.3c.7646_B20201211 allows remote attackers to execute arbitrary commands via GET requests. downloadFlile.cgi reads the GET query from QUERY_STRING and passes a controllable parameter name to a shell command without neutralizing command separators. No authentication or user interaction is required, and successful injection executes commands with the CGI process's privileges.

CVSS severity9.8
Critical
EPSS probability37.84%
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 TOTOLINK EX200 firmware 4.0.3c.7646_B20201211 allows remote attackers to execute arbitrary commands via GET requests. downloadFlile.cgi reads the GET query from QUERY_STRING and passes a controllable parameter name to a shell command without neutralizing command separators. No authentication or user interaction is required, and successful injection executes commands with the CGI process's privileges.

The record

CVE
CVE-2021-43711
Published
Jan 4, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-77, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 4, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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 exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059.004Unix Shell

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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