CVE-2020-26728Public exploitNetwork attack vector

Unauthenticated command execution via unsanitized guestuser parameter

Published Feb 11, 2022 · Updated Aug 4, 2024

Command injection in Tenda AC9 firmware 15.03.06.42_multi and 15.03.05.19(6318)_CN allows remote attackers to execute commands. The SetSambaCfg handler in the httpd web server passes the POST guestuser value directly to doSystem, allowing shell metacharacters to alter the command. No authentication or user interaction is required, and injected commands run in the router's operating context.

CVSS severity9.8
Critical
EPSS probability3.77%
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 Tenda AC9 firmware 15.03.06.42_multi and 15.03.05.19(6318)_CN allows remote attackers to execute commands. The SetSambaCfg handler in the httpd web server passes the POST guestuser value directly to doSystem, allowing shell metacharacters to alter the command. No authentication or user interaction is required, and injected commands run in the router's operating context.

The record

CVE
CVE-2020-26728
Published
Feb 11, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 11, 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

T1190Exploit Public-Facing Application
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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