From owner-freebsd-security@freebsd.org Tue Sep 13 21:27:33 2016 Return-Path: Delivered-To: freebsd-security@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A7BD1BD9FA9 for ; Tue, 13 Sep 2016 21:27:33 +0000 (UTC) (envelope-from lyndon@orthanc.ca) Received: from orthanc.ca (orthanc.ca [IPv6:2607:f2f8:abf8::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "orthanc.ca", Issuer "Let's Encrypt Authority X1" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 91F1FF49 for ; Tue, 13 Sep 2016 21:27:33 +0000 (UTC) (envelope-from lyndon@orthanc.ca) Received: from localhost (localhost [IPv6:::1]) by orthanc.ca (8.15.2/8.15.2) with ESMTPS id u8DLRM5I054589 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 13 Sep 2016 14:27:22 -0700 (PDT) (envelope-from lyndon@orthanc.ca) Date: Tue, 13 Sep 2016 14:27:22 -0700 (PDT) From: Lyndon Nerenberg To: "Ronald F. Guilmette" cc: freebsd-security@freebsd.org Subject: Re: ftpd leaks info which might be useful to an attacker In-Reply-To: <68595.1473800829@segfault.tristatelogic.com> Message-ID: References: <68595.1473800829@segfault.tristatelogic.com> User-Agent: Alpine 2.20 (BSF 67 2015-01-07) Organization: The Frobozz Magic Homing Pigeon Company MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Spam-Status: No, score=-0.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, MISSING_DATE,MISSING_FROM,MISSING_MID autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on orthanc.ca X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Sep 2016 21:27:33 -0000 > Thinking about how the contents of these files affects the behavior of > the ftp DIR command caused me to realize that I actually would prefer > it if there were some some option available for ftpd which would cause > it to display only something like ---- where it currently attempts to > print either a user ID name or number or a group ID name or number. I would be concerned about programs that parse that output choking on a field of only hyphens. It's likely safer to just report the uid and gid as 0 (or 666, or some other made-up number of your choice). --lyndon