Return-Path: owner-bugtraq@SECURITYFOCUS.COM Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="a8Wt8u1KmwUX3Y2C" X-Mailer: Mutt 1.0pre2i Message-ID: <19990929145251.A12132@austin.ibm.com> Date: Wed, 29 Sep 1999 14:52:51 -0500 Reply-To: "Troy A. Bollinger" Sender: Bugtraq List From: "Troy A. Bollinger" Subject: Re: Fw: Remote bufferoverflow exploit for ftpd from AIX 4.3.2 running on an RS6000. (power) X-To: "W.H.J.Pinckaers" X-cc: BUGTRAQ@SECURITYFOCUS.COM To: BUGTRAQ@SECURITYFOCUS.COM In-Reply-To: <1DF26A56012@cpedu1.cpedu.rug.nl> --a8Wt8u1KmwUX3Y2C Content-Type: text/plain; charset=us-ascii Quoting W.H.J.Pinckaers (W.H.J.Pinckaers@CPEDU.RUG.NL): > sq01@Yorku.Ca Wrote > > > > > > >Short of disabling ftpd completely, is there a work-around that will not > > >affect our users ? > > > We released an advisory this morning but I haven't seen it on bugtraq yet. I've attached it below in case it got lost. It includes instructions on where to download the workaround. > > You can check this by running something like: > perl -e 'print "A" x 5000' | nc -v -v aix 21 > (effectivly sending a long string to the aix ftpd) > if this returns immediatly (ftpd dies) you are vulnerable if it returns a > lot of 500 AAAAAAA... unknown command or something like that > errors you are NOT vulnerable. > Be careful. Sometimes ftpd prints an error message but still core dumps. All unpatched 4.3.x machines are vulnerable. -- Troy Bollinger troy@austin.ibm.com AIX Security Development security-alert@austin.ibm.com PGP keyid: 1024/0xB7783129 Troy's opinions are not IBM policy --a8Wt8u1KmwUX3Y2C Content-Type: text/plain; charset=us-ascii Content-Description: ftpd.alert Content-Disposition: attachment; filename="ftpd.alert" ---FOR PUBLIC RELEASE --- -----BEGIN PGP SIGNED MESSAGE----- - --ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT-- - ---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE--- ======= ============ ====== ====== ======= ============== ======= ======= === === ==== ====== ====== === =========== ======= ======= === =========== === ======= === === === ==== === ===== === ======= ============== ===== === ===== ======= ============ ===== = ===== EMERGENCY RESPONSE SERVICE SECURITY VULNERABILITY ALERT 29 September 1999 11:30 GMT Number: ERS-SVA-E01-1999:004.1 =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: Remote buffer overflow in ftpd daemon. PLATFORMS: IBM AIX(r) 4.3.x SOLUTION: Apply the fixes listed below. THREAT: Remote users can become root. ============================================================================== DETAILED INFORMATION I. Description A buffer overflow vulnerability has been found in the AIX 4.3.x ftpd daemon that allows remote attackers to gain root access. Example exploit code has been publically released. II. Solutions A. How to alleviate the problem A temporary fix is available via anonymous ftp from: ftp://aix.software.ibm.com/aix/efixes/security/ftpd.tar.Z Filename sum md5 ================================================================= ftpd 02584 147 4577818c9c95b47ffc915ab750f36bd3 This temporary fix has not been fully regression tested. Use the following steps (as root) to install the temporary fix: 1. Uncompress and extract the fix. # uncompress < ftpd.tar.Z | tar xf - # cd ftpd 2. Replace the vulnerable ftpd. # mv /usr/sbin/ftpd /usr/sbin/ftpd.before_security_fix # chown root.system /usr/sbin/ftpd.before_security_fix # chmod 0 /usr/sbin/ftpd.before_security_fix # cp ./ftpd /usr/sbin/ftpd # chown root.system /usr/sbin/ftpd # chmod 4554 /usr/sbin/ftpd B. Official fix IBM is working on the following fixes which will be available soon. AIX 4.2.x and earlier: not vulnerable AIX 4.3.x: IY04477 III. Obtaining Fixes IBM AIX APARs may be ordered using Electronic Fix Distribution (via the FixDist program), or from the IBM Support Center. For more information on FixDist, and to obtain fixes via the Internet, please reference http://techsupport.services.ibm.com/support/rs6000.support/downloads or send electronic mail to "aixserv@austin.ibm.com" with the word "FixDist" in the "Subject:" line. To facilitate ease of ordering all security related APARs for each AIX release, security fixes are periodically bundled into a cumulative APAR. For more information on these cumulative APARs including last update and list of individual fixes, send electronic mail to "aixserv@austin.ibm.com" with the word "subscribe Security_APARs" in the "Subject:" line. IV. Contact Information Comments regarding the content of this announcement can be directed to your local IBM support center or to: security-alert@austin.ibm.com To request the PGP public key that can be used to encrypt new AIX security vulnerabilities, send email to security-alert@austin.ibm.com with a subject of "get key". If you would like to subscribe to the AIX security newsletter, send a note to aixserv@austin.ibm.com with a subject of "subscribe Security". To cancel your subscription, use a subject of "unsubscribe Security". To see a list of other available subscriptions, use a subject of "help". IBM and AIX are a registered trademark of International Business Machines Corporation. All other trademarks are property of their respective holders. =============================================================================== IBM's Internet Emergency Response Service (IBM-ERS) is a subscription-based Internet security response service that includes computer security incident response and management, regular electronic verification of your Internet gateway(s), and security vulnerability alerts similar to this one that are tailored to your specific computing environment. By acting as an extension of your own internal security staff, IBM-ERS's team of Internet security experts helps you quickly detect and respond to attacks and exposures across your Internet connection(s). As a part of IBM's Business Recovery Services organization, the IBM Internet Emergency Response Service is a component of IBM's SecureWay(tm) line of security products and services. From hardware to software to consulting, SecureWay solutions can give you the assurance and expertise you need to protect your valuable business resources. To find out more about the IBM Internet Emergency Response Service, send an electronic mail message to ers-sales@ers.ibm.com, or call 1-800-599-9950. IBM-ERS maintains a site on the World Wide Web at http://www.ers.ibm.com/. Visit the site for information about the service, copies of security alerts, team contact information, and other items. IBM-ERS uses Pretty Good Privacy* (PGP*) as the digital signature mechanism for security vulnerability alerts and other distributed information. The IBM-ERS PGP* public key is available from http://www.ers.ibm.com/team-info/pgpkey.html. "Pretty Good Privacy" and "PGP" are trademarks of Philip Zimmermann. IBM-ERS is a Member Team of the Forum of Incident Response and Security Teams (FIRST), a global organization established to foster cooperation and response coordination among computer security teams worldwide. Copyright 1999 International Business Machines Corporation. The information in this document is provided as a service to customers of the IBM Emergency Response Service. Neither International Business Machines Corporation, nor any of its employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, complete- ness, or usefulness of any information, apparatus, product, or process contained herein, or represents that its use would not infringe any privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by IBM or its subsidiaries. The views and opinions of authors expressed herein do not necessarily state or reflect those of IBM or its subsidiaries, and may not be used for advertising or product endorsement purposes. The material in this security alert may be reproduced and distributed, without permission, in whole or in part, by other security incident response teams (both commercial and non-commercial), provided the above copyright is kept intact and due credit is given to IBM-ERS. This security alert may be reproduced and distributed, without permission, in its entirety only, by any person provided such reproduction and/or distribution is performed for non-commercial purposes and with the intent of increasing the awareness of the Internet community. - ---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE--- - --ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT-- -----BEGIN PGP SIGNATURE----- Version: 2.7.1 iQCVAwUBN/IAOfWDLGpfj4rlAQEPDgP9EqPnF8dhoamLDs12NS9X9zHwr9CHHdg8 RQGGGs7lyah8LSyrMD6jF5vAxUhVmG160uJt9JgX+oOm/WzqVwcBadUqz0aMmdeA owP02VRnQBHwFOMB5A2+oRBPLlEg8qWLdfW4uvZidab+lTs/IerfY9ZWaWPM77iG 8ChzywhDpF0= =qzwC -----END PGP SIGNATURE----- --a8Wt8u1KmwUX3Y2C--