876907 – (CVE-2021-36369) <net-misc/dropbear-2022.82: forwarded agent abuse

Bug 876907 (CVE-2021-36369) - <net-misc/dropbear-2022.82: forwarded agent abuse

Summary: <net-misc/dropbear-2022.82: forwarded agent abuse

Status:	RESOLVED FIXED

Alias:	CVE-2021-36369

Product:	Gentoo Security
Classification:	Unclassified
Component:	Vulnerabilities (show other bugs)
Hardware:	All Linux

Importance:	Normal minor (vote)
Assignee:	Gentoo Security

URL:	https://github.com/mkj/dropbear/relea...
Whiteboard:	B4 [glsa?]
Keywords:

Depends on:	877023
Blocks:
	Show dependency tree

Reported:	2022-10-13 01:52 UTC by John Helmert III
Modified:	2023-03-06 04:32 UTC (History)
CC List:	1 user (show)

See Also:
Package list:
Runtime testing required:	---

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Description John Helmert III archtester

2022-10-13 01:52:15 UTC

CVE-2021-36369 (https://github.com/mkj/dropbear/pull/128):

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.

Please stabilize 2022.82.

Comment 1 John Helmert III archtester

2022-11-28 04:02:30 UTC

Please cleanup

Comment 2 Larry the Git Cow gentoo-dev

2023-03-01 13:44:50 UTC

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=2d6a3e2a78ea3a3a82e933bbc71f25b995aa7b5c

commit 2d6a3e2a78ea3a3a82e933bbc71f25b995aa7b5c
Author:     Viorel Munteanu <ceamac@gentoo.org>
AuthorDate: 2023-03-01 12:53:53 +0000
Commit:     Viorel Munteanu <ceamac@gentoo.org>
CommitDate: 2023-03-01 13:41:28 +0000

    net-misc/dropbear: drop 2020.81-r3
    
    Bug: https://bugs.gentoo.org/876907
    Signed-off-by: Viorel Munteanu <ceamac@gentoo.org>

 net-misc/dropbear/Manifest                   |   1 -
 net-misc/dropbear/dropbear-2020.81-r3.ebuild | 125 ---------------------------
 2 files changed, 126 deletions(-)

Comment 3 John Helmert III archtester

2023-03-06 04:32:03 UTC

Thanks! Complex/high requirements to exploit, so no GLSA. All done!