PT-2022-10511 · Dropbear+3 · Dropbear+3

Manfred Kaiser · Published 2022-04-01 · Updated 2025-05-15 · CVE-2021-36369

Positive Technologies (AI Summary)

CVSS v2.0

7.8

High

Base vector

AV:N/AC:L/Au:N/C:N/I:C/A:N

Name of the Vulnerable Software and Affected Versions Dropbear versions through 2020.81

Description An issue in the client-side SSH code allows an SSH server to change the login process in its favor due to a non-RFC-compliant check of available authentication methods. This can bypass additional security measures such as FIDO2 tokens or SSH-Askpass, enabling an attacker to abuse a forwarded agent for logging on to another server unnoticed.

Recommendations For Dropbear versions through 2020.81, update to a version later than 2020.81 to resolve the issue.

Fix

Improper Authentication

Weakness Enumeration

CWE-287

Related Identifiers

ALT-PU-2022-2113

ALT-PU-2024-4252

ALT-PU-2024-7377

BDU:2025-13194

CVE-2021-36369

DLA-3187-1

MGASA-2022-0436

USN-7292-1

Affected Products

Alt Linux

Dropbear

Linuxmint

Ubuntu

References · 20

• https://advisories.mageia.org/MGASA-2022-0436.html · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-36369 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-36369 · Vendor Advisory
• https://osv.dev/vulnerability/USN-7292-1 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-36369 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-36369 · Security Note
• https://ubuntu.com/security/notices/USN-7292-1 · Vendor Advisory
• https://osv.dev/vulnerability/MGASA-2022-0436 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-13194 · Security Note
• https://ubuntu.com/security/CVE-2023-48795 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-3187-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-36369 · Security Note
• https://osv.dev/vulnerability/CVE-2021-36369 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-36369 · Vendor Advisory
• https://github.com/mkj/dropbear/releases · Note