How severe is CVE-2021-45099?

CVE-2021-45099 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-45099 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45099?

CVE-2021-45099 affects Ssh & Web Terminal Project Ssh & Web Terminal. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45099?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-45099 published?

CVE-2021-45099 was published on 2021-12-16 and last updated on 2026-06-17.

CVE-2021-45099

CVE-2021-45099 is a high-severity vulnerability in Ssh & Web Terminal Project Ssh & Web Terminal with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Ssh & Web Terminal Project Ssh & Web Terminal
Published: 2021-12-16
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2021-45099?: 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
How severe is CVE-2021-45099?: CVE-2021-45099 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-45099 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45099?: CVE-2021-45099 affects Ssh & Web Terminal Project Ssh & Web Terminal. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45099?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-45099 published?: CVE-2021-45099 was published on 2021-12-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ssh_\&_web_terminal_project:ssh_\&_web_terminal:*:*:*:*:*:home_assistant:*:*