Is CVE-2021-36369 in the CISA KEV catalog?

No. CVE-2021-36369 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-36369?

CVE-2021-36369 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-36369?

CVE-2021-36369 has an EPSS score of 1.35% (68th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-36369?

Upgrade dropbear on debian 11 to 2020.81-3+deb11u1 or later. Fixes are available for 3 affected products.

CVE & CISA-KEV Catalog

CVE-2021-36369

HIGH

7.5

CVSS v3

NVD

Description

An issue was discovered in Dropbear through 2020.81. Due to a non-RFC-compliant check of the available authentication methods in the client-side SSH code, it is possible for an SSH server to change the login process in its favor. This attack can bypass additional security measures such as FIDO2 tokens or SSH-Askpass. Thus, it allows an attacker to abuse a forwarded agent for logging on to another server unnoticed.

CWE-287Improper Authentication

How to fix

Remediation Available

dropbearDebian

Fixed in:2020.81-3+deb11u1CVE-2021-36369

Fixed in:2022.82-1CVE-2021-36369

dropbearUbuntu

Fixed in:2017.75-3ubuntu0.1~esm1USN-7292-1

Fixed in:2019.78-2ubuntu0.1~esm1USN-7292-1

Fixed in:2020.81-5ubuntu0.1USN-7292-1

dropbear-binUbuntu

Fixed in:2017.75-3ubuntu0.1~esm1USN-7292-1

Fixed in:2019.78-2ubuntu0.1~esm1USN-7292-1

Fixed in:2020.81-5ubuntu0.1USN-7292-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Intelligence

1.35%probability of exploitation in 30 days

68thpercentile

Moderate risk: more likely to be exploited than 68% of all known CVEs.

References

Third-Party Advisory4

Related Vulnerabilities

Other CWE-287 (Improper Authentication) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-35082	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-35078	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2017-7921	Critical	9.8	100%	KEV	-
CVE-2024-7593	Critical	9.8	100%	KEV	-
CVE-2023-46805	High	8.2	100%	KEV + Ransom	-
CVE-2022-40684	Critical	9.8	100%	KEV + Ransom	Fix

Embed a live status badge for CVE-2021-36369

Markdown

[![CVE-2021-36369](https://tridentstack.com/cve/badge/CVE-2021-36369.svg)](https://tridentstack.com/cve/CVE-2021-36369)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-36369"><img src="https://tridentstack.com/cve/badge/CVE-2021-36369.svg" alt="CVE-2021-36369"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-05-15.