CVE-2021-36369 Auth bypass in n/a
A non-RFC-compliant authentication check in Dropbear allows attackers to bypass security measures like FIDO2 tokens and abuse forwarded agents for unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-36369?
CVE-2021-36369 is a high-severity authentication bypass vulnerability in Debian Debian Linux, published on 12 Oct 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-287
Which versions are affected by CVE-2021-36369?
It affects 2 products.
Products include Debian Debian Linux, Dropbear Ssh Project Dropbear Ssh.
How do I fix CVE-2021-36369?
Apply the vendor's patch.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2021-36369 being exploited?
There is no known exploitation of CVE-2021-36369 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2021-36369, DLA-3187-1, GHSA-mwx5-864v-x3jc, MGASA-2022-0436, UBUNTU-CVE-2021-36369.