Mageia 2022-0436: dropbear security update | LinuxSecurity.com
MGASA-2022-0436 - Updated dropbear packages fix security vulnerability

Publication date: 24 Nov 2022
URL: https://advisories.mageia.org/MGASA-2022-0436.html
Type: security
Affected Mageia releases: 8
CVE: CVE-2021-36369

Updated dropbear package fixes a security vulnerability in dbclient:.
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.

The fix adds a new option, DisableTrivialAuth, to dbclient to disable this
attack vector. Invoke dbclient as
"dbclient -o DisableTrivialAuth=yes localhost …" to enable this mitigation
on each dbclient invocation.

References:
- https://bugs.mageia.org/show_bug.cgi?id=31119
- https://github.com/mkj/dropbear/pull/128
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-36369

SRPMS:
- 8/core/dropbear-2020.81-1.1.mga8

Mageia 2022-0436: dropbear security update

Updated dropbear package fixes a security vulnerability in dbclient:

Summary

Updated dropbear package fixes a security vulnerability in dbclient:. 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.
The fix adds a new option, DisableTrivialAuth, to dbclient to disable this attack vector. Invoke dbclient as "dbclient -o DisableTrivialAuth=yes localhost …" to enable this mitigation on each dbclient invocation.

References

- https://bugs.mageia.org/show_bug.cgi?id=31119

- https://github.com/mkj/dropbear/pull/128

- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-36369

Resolution

MGASA-2022-0436 - Updated dropbear packages fix security vulnerability

SRPMS

- 8/core/dropbear-2020.81-1.1.mga8

Severity
Publication date: 24 Nov 2022
URL: https://advisories.mageia.org/MGASA-2022-0436.html
Type: security
CVE: CVE-2021-36369

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