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CERT^® Advisory CA-1993-06 wuarchive ftpd Vulnerability

Original issue date: April 9, 1993
Last revised: September 19, 1997
Attached copyright statement

A complete revision history is at the end of this file.

The CERT Coordination Center has received information concerning a vulnerability in versions of wuarchive ftpd available before April 8, 1993. Vulnerable wuarchive ftpd versions were available from wuarchive.wustl.edu:/packages/ftpd.wuarchive.shar and many other anonymous FTP sites.

We strongly recommend that any site using versions of wuarchive ftpd dating prior to April 8, 1993, immediately take corrective action or remove this service.

I. Description

A vulnerability exists in the access control mechanism in this version of ftpd.

II. Impact

Anyone (remote or local) can potentially gain access to any account including root on a host running this version of ftpd.

III. Solution

Affected sites may choose to disable anonymous FTP service until they have corrected this problem.

Affected sites can correct this problem through one of the following two procedures:

                                              Size      Checksum
/packages/wuarchive-ftpd/wu-ftpd-2.0.shar    421953      08786
/packages/wuarchive-ftpd/wu-ftpd-2.0.tar     491520      27466

*** ftpd.c.orig
- --- ftpd.c
***************
*** 413,418 ****
- --- 413,420 ----
                end_login();
        }
  
+       anonymous = 0;
+ 
        if (!strcasecmp(name, "ftp") || !strcasecmp(name, "anonymous")) {
                if (checkuser("ftp") || checkuser("anonymous")) {
                        reply(530, "User %s access denied.", name);

The CERT Coordination Center wishes to thank Scott Paisley, Computer Systems Support Manager, Factory Automated Systems Division, N.I.S.T., for informing us of this vulnerability. We would also like to thank Chris Myers, Washington University, for his quick response to this problem.

This document is available from: http://www.cert.org/advisories/CA-1993-06.html

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Revision History

September 19, 1997  Attached Copyright Statement