CVE-2021-45099Public exploitNetwork attack vector

Command execution via addon.stdin service

Published Dec 16, 2021 · Updated Nov 18, 2024

An access-control issue in Home Assistant SSH & Web Terminal before 10.0.0 allows attackers to run add-on commands via addon.stdin. The service accepted attacker-controlled input and executed commands inside the add-on container, creating an attack surface documented as requiring complex social engineering. Exploitation depends on persuading a victim through that sequence; the vendor disputes that the behavior is a vulnerability and removed the service as defense in depth.

CVSS severity8.8
High
EPSS probability1.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An access-control issue in Home Assistant SSH & Web Terminal before 10.0.0 allows attackers to run add-on commands via addon.stdin. The service accepted attacker-controlled input and executed commands inside the add-on container, creating an attack surface documented as requiring complex social engineering. Exploitation depends on persuading a victim through that sequence; the vendor disputes that the behavior is a vulnerability and removed the service as defense in depth.

The record

CVE
CVE-2021-45099
Published
Dec 16, 2021
Updated
Nov 18, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 18, 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

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/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

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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