CERT® Advisory CA-1992-09 AIX Anonymous FTP VulnerabilityOriginal issue date: April 27, 1992
Last revised: September 19, 1997
Attached copyright statement
A complete revision history is at the end of this file.
The Computer Emergency Response Team/Coordination Center (CERT/CC) has received information concerning a vulnerability in the anonymous FTP configuration in all versions of AIX.
IBM is aware of this problem and a fix is available as apar number "ix23944". This patch is available for all AIX releases from "GOLD".
IBM customers may call IBM Support (800-237-5511) and ask that the fix be shipped to them. Patches may be obtained outside the U.S. by contacting your local IBM representative. The fix will appear in the upcoming 2009 update and the next release of AIX.
Previous versions of the anonymous FTP installation script, /usr/lpp/tcpip/samples/anon.ftp, incorrectly configured various files and directories.
Remote users can execute unauthorized commands and gain access to the system if anonymous FTP has been installed.
A. Obtain the fix from IBM Support.
The fix contains three files:
the fix installation script (install.a23944),
and an archive containing the updated files (PATCH.a23944.Z).
B. Install the fix following the instructions in the README file.
The CERT/CC would like to thank Charles McGuire of the Computer Science Department, the University of Montana for bringing this security vulnerability to our attention and IBM for their response to the problem.
This document is available from: http://www.cert.org/advisories/CA-1992-09.html
CERT/CC Contact Information
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) / EDT(GMT-4) Monday through Friday; they are on call for emergencies during other hours, on U.S. holidays, and on weekends.
We strongly urge you to encrypt sensitive information sent by email. Our public PGP key is available from
If you prefer to use DES, please call the CERT hotline for more information.
Getting security information
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Conditions for use, disclaimers, and sponsorship information
Copyright 1992 Carnegie Mellon University.
September 19,1997 Attached copyright statement