CVE-2021-20122

Root command execution via unsanitized TR-069 parameters

Published Oct 11, 2021 · Updated Aug 3, 2024

Command injection in TELUS Wi-Fi Hub firmware 3.00.20 allows remote authenticated users on the LAN to execute commands as root via tr69_cmd.cgi. Parameters from tr69.htm are inserted into system() command strings without sanitization, allowing shell metacharacters to run attacker-supplied commands. Exploitation requires a super-user account or an authentication-bypass path such as CVE-2021-20090; successful attacks can compromise confidentiality, integrity, and availability of the gateway.

CVSS severity9.0
Critical
EPSS probability6.53%
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 TELUS Wi-Fi Hub firmware 3.00.20 allows remote authenticated users on the LAN to execute commands as root via tr69_cmd.cgi. Parameters from tr69.htm are inserted into system() command strings without sanitization, allowing shell metacharacters to run attacker-supplied commands. Exploitation requires a super-user account or an authentication-bypass path such as CVE-2021-20090; successful attacks can compromise confidentiality, integrity, and availability of the gateway.

The record

CVE
CVE-2021-20122
Published
Oct 11, 2021
Updated
Aug 3, 2024
Vendor
TELUS
Product
TELUS Wi-Fi Hub
Classifications
CWE-78, T1059
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

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

  1. Affected versionversion=3.00.20

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

TELUS · TELUS Wi-Fi Hubversion=3.00.20

Published CVSS scores

9.0NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
7.2NVDCVSS:3.1/AV:N/AC:L/PR:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

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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