CVE-2021-45099: The addon.stdin service in addon-ssh (aka Home Assistant Community Add-on: SSH & Web Terminal) before 10.0.0 h

Q: How do I fix CVE-2021-45099?

ssh \& web terminal: upgrade to 10.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-45099 being exploited?

CVE-2021-45099 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-45099 affect?

CVE-2021-45099 affects ssh \& web terminal. Severity is high (CVSS 8.8). The addon.stdin service in addon-ssh (aka Home Assistant Community Add-on: SSH & Web Terminal) before 10.0.0 has an attack surface that requires social engineering. NOTE: the vendor does not agree that this is a vulnerability; however, addo

Q: How urgent is CVE-2021-45099?

Priority 54/100. High severity; Public exploit reference

This month

HIGH 8.8UPGRADE

CVE-2021-45099 is a high-severity flaw (CVSS 8.8) affecting ssh \& web terminal. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The addon.stdin service in addon-ssh (aka Home Assistant Community Add-on: SSH & Web Terminal) before 10.0.0 has an attack surface that requires social engineering. NOTE: the vendor does not agree that this is a vulnerability; however, addon.stdin was removed as a defense-in-depth measure against complex social engineering situations

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.3% (top 29%)
CISA exploited list	No
Published	2021-12-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: ssh \& web terminal project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-12-16 05:15 UTCPublished CVE record published
2026-06-17 04:13 UTCUpdated Record last modified

ssh \& web terminal project ssh \& web terminal UPGRADE

Affected: < 10.0.0

Fixed in: 10.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ssh--web-terminal || rpm -q ssh--web-terminal || ssh--web-terminal --version

2. UPGRADE to 10.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ssh--web-terminal

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ssh--web-terminal

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-45099?

ssh \& web terminal: upgrade to 10.0.0. Exact commands for each OS are on this page.

Is CVE-2021-45099 being exploited?

CVE-2021-45099 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-45099 affect?

CVE-2021-45099 affects ssh \& web terminal. Severity is high (CVSS 8.8). The addon.stdin service in addon-ssh (aka Home Assistant Community Add-on: SSH & Web Terminal) before 10.0.0 has an attack surface that requires social engineering. NOTE: the vendor does not agree that this is a vulnerability; however, addo

How urgent is CVE-2021-45099?

Priority 54/100. High severity; Public exploit reference

Software pages

Home Assistant vulnerabilities

References

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