From nobody Thu Jan 30 04:52:12 2025 X-Original-To: freebsd-security@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Yk6851VX2z5mRWK for ; Thu, 30 Jan 2025 04:52:21 +0000 (UTC) (envelope-from shuriku@shurik.kiev.ua) Received: from mail.flex-it.com.ua (mail.flex-it.com.ua [193.239.74.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4Yk6845lg9z43Ch for ; Thu, 30 Jan 2025 04:52:20 +0000 (UTC) (envelope-from shuriku@shurik.kiev.ua) Authentication-Results: mx1.freebsd.org; none Received: from [188.231.181.61] (helo=[10.2.1.129]) by mail.flex-it.com.ua with esmtpsa (TLS1.3) tls TLS_AES_128_GCM_SHA256 (Exim 4.98 (FreeBSD)) (envelope-from ) id 1tdMXJ-000000002Hb-2aBR for freebsd-security@freebsd.org; Thu, 30 Jan 2025 06:52:17 +0200 Message-ID: Date: Thu, 30 Jan 2025 06:52:12 +0200 List-Id: Security issues List-Archive: https://lists.freebsd.org/archives/freebsd-security List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: freebsd-security@freebsd.org Sender: owner-freebsd-security@FreeBSD.org MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: FreeBSD Security Advisory FreeBSD-SA-25:01.openssh To: freebsd-security@freebsd.org References: <20250129213102.E4CFA27A5@freefall.freebsd.org> Content-Language: en-US From: Oleksandr Kryvulia In-Reply-To: <20250129213102.E4CFA27A5@freefall.freebsd.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ACL-Warn: SPF failed. 188.231.181.61 is not allowed to send mail from shurik.kiev.ua. X-Rspamd-Queue-Id: 4Yk6845lg9z43Ch X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:35297, ipnet:193.239.72.0/22, country:UA] 29.01.25 23:31, FreeBSD Security Advisories: > ============================================================================= > FreeBSD-SA-25:01.openssh Security Advisory >                                                           The FreeBSD > Project > > Topic:          OpenSSH Keystroke Obfuscation Bypass > > Category:       contrib > Module:         openssh > Announced:      2025-01-29 > Credits:        Philippos Giavridis > Credits:        Jacky Wei En Kung, Daniel Hugenroth and >                 Alastair Beresford (University of Cambridge) > Affects:        FreeBSD 14.1 > Corrected:      2024-07-15 18:45:16 UTC (stable/14, 14.2-STABLE) >                 2025-01-29 18:55:25 UTC (releng/14.1, 14.1-RELEASE-p7) >                 2024-08-01 15:03:50 UTC (stable/13, 13.4-STABLE) > CVE Name:       CVE-2024-39894 > > For general information regarding FreeBSD Security Advisories, > including descriptions of the fields above, security branches, and the > following sections, please visit . > > I.   Background > > OpenSSH is an implementation of the SSH protocol suite, providing an > encrypted and authenticated transport for a variety of services, including > remote shell access. > > OpenSSH version 9.5 introduced a mechanism to mitigate keystroke timing > attacks by "sending interactive traffic at fixed intervals when there is > only a small amount of data being sent." > > II.  Problem Description > > A logic error in the ssh(1) ObscureKeystrokeTiming feature (on by default) > rendered this feature ineffective. > > III. Impact > > A passive observer could detect which network packets contain real > keystrokes, > and infer the specific characters being transmitted from packet timing. > > IV.  Workaround > > No workaround is available.  This bug does not affect connections when > ObscureKeystrokeTiming was disabled or sessions where no TTY was > requested. > > V.   Solution > > Upgrade your vulnerable system to a supported FreeBSD stable or > release / security branch (releng) dated after the correction date. > > Perform one of the following: > > 1) To update your vulnerable system via a binary patch: > > Systems running a RELEASE version of FreeBSD on the amd64 or arm64 > platforms, > or the i386 platform on FreeBSD 13, can be updated via the > freebsd-update(8) > utility: > > # freebsd-update fetch > # freebsd-update install > # shutdown -r +10min "Rebooting for a security update" > > 2) To update your vulnerable system via a source code patch: > > The following patches have been verified to apply to the applicable > FreeBSD release branches. > > a) Download the relevant patch from the location below, and verify the > detached PGP signature using your PGP utility. > > [FreeBSD 14.1] > # fetch https://security.FreeBSD.org/patches/SA-25:01/openssh.patch > # fetch https://security.FreeBSD.org/patches/SA-25:01/openssh.patch.asc > # gpg --verify openssh.patch.asc > > b) Apply the patch.  Execute the following commands as root: > > # cd /usr/src > # patch < /path/to/patch > > c) Recompile the operating system using buildworld and installworld as > described in . > > VI.  Correction details > > This issue is corrected as of the corresponding Git commit hash in the > following stable and release branches: > > Branch/path                             Hash Revision > ------------------------------------------------------------------------- > stable/14/                              bf9a275b24f6 stable/14-n268158 > releng/14.1/                            88d5d8108711 releng/14.1-n267735 > stable/13/                              79853e40abd8 stable/13-n258171 > ------------------------------------------------------------------------- > > Run the following command to see which files were modified by a > particular commit: > > # git show --stat > > Or visit the following URL, replacing NNNNNN with the hash: > > > > To determine the commit count in a working tree (for comparison against > nNNNNNN in the table above), run: > > # git rev-list --count --first-parent HEAD > > VII. References > > > > The latest revision of this advisory is available at > Do we really need to reboot or restart sshd is enough?