CVE-2021-28961Network attack vector

Authenticated command execution via unquoted DDNS fields

Published Mar 21, 2021 · Updated Aug 3, 2024

Command injection in OpenWrt luci-app-ddns 19.07.0 through 19.07.7 allows remote authenticated users to execute arbitrary shell commands. The DDNS detail model appends multiple LuCI form values directly to command strings passed to SYS.call without shell quoting. Exploitation requires authenticated LuCI access and the optional luci-app-ddns package; injected commands run in the device shell.

CVSS severity8.8
High
EPSS probability1.53%
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 OpenWrt luci-app-ddns 19.07.0 through 19.07.7 allows remote authenticated users to execute arbitrary shell commands. The DDNS detail model appends multiple LuCI form values directly to command strings passed to SYS.call without shell quoting. Exploitation requires authenticated LuCI access and the optional luci-app-ddns package; injected commands run in the device shell.

The record

CVE
CVE-2021-28961
Published
Mar 21, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-78, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 21, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

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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