<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> /* *\ / * * \ / * * \ / * * \ / * System Vulnerabilities * \ | * * | | * * | | * * | | * Another Modernz Presentation * | | * * | \ * by * / \ * Multiphage * / \ * * / \ * (C)opyright June 9th, 1992 * / \ * */ ********************************************************* <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> ******************************************************************************* The Modernz can be contacted at: MATRIX BBS WOK-NOW! World of Kaos NOW! World of Knowledge NOW! St. Dismis Institute - Sysops: Wintermute Digital-demon (908) 905-6691 (908) WOK-NOW! (908) 458-xxxx 1200/2400/4800/9600 14400/19200/38400 Home of Modernz Text Philez <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>< <*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> TANSTAAFL Pheonix Modernz The Church of Rodney - Sysop: Tal Meta (908) 830-TANJ (908) 830-8265 Home of TANJ Text Philez <*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*> CyberChat Sysop: Hegz (908)506-6651 (908)506-7637 300/1200/2400/4800/9600 14400/19200/38400 Modernz Site TLS HQ <><><><><><><><><><><><><><<><<><><><><><><><><><><><><><><><><><><><><><><><>< The Global Intelligence Center World UASI Headquarters! Pennsylvania SANsite! (412) 475-4969 300/1200/2400/9600 24 Hours! SysOp: The Road Warrior <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>< The Lost Realm Western PA UASI site! Western PA. SANfranchise (412) 588-5056 300/1200/2400 SysOp: Orion Buster <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>< The Last Outpost PowerBBS Support Board UASI ALPHA Division NorthWestern PA UASI site! (412) 662-0769 300/1200/2400 24 hours! SysOp: The Almighty Kilroy <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>< Hellfire BBS SANctuary World Headquarters! New Jersey UASI site! (908) 495-3926 300/1200/2400 24 hours! SysOp: Red <*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*> BlitzKreig BBS Home of TAP (502)499-8933 <*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*><*> IBM is aware of this problem and a fix is available as apar number "ix22628". This patch is available for all AIX releases from "GOLD" to the current release. NOTE: THIS IS AN UPDATED PATCH FROM ONE RECENTLY MADE AVAILABLE and fixes a security hole in the original patch. The SCCS id of the correct patch is tftpd.c 1.13.1.3 (*not* 1.13.1.2 or earlier versions). This can be checked using the following "what" command. .More.. % what /etc/tftpd /etc/tftpd: 56 1.13.1.3 tftpd.c, tcpip, tcpip312 10/10/91 09:01:48 tftpsubs.c 1.2 com/sockcmd/tftpd,3.1.2,9048312 10/8/89 17:40:55 IBM customers may call IBM Support (800-237-5511) and ask that the fix be shipped to them. The fix will appear in the upcoming 2009 update and the next release of AIX. --------------------------------------------------------------------------- I. Description Previous versions of tftpd did not provide a method for restricting TFTP access. II. Impact If TFTP is enabled at your site, anyone on the Internet can retrieve copies of your site's world-readable files, such as /etc/passwd. III. Solution A. Sites that do not need to allow tftp access should disable it. This can be done by editing /etc/inetd.conf and deleting or commenting out the tftpd line: #tftp dgram udp wait nobody /etc/tftpd tftpd -n and then, as root, restarting inetd with the "refresh" command. # refresh -s inetd For more details on starting/stopping tftp, refer to documentation for the System Resource Controller (SRC) or the System Management Interface Tool (SMIT). B. Sites that must run tftpd (for example, to support X terminals) should obtain and install the above patch AND create a /etc/tftpaccess.ctl file to restrict the files that are accessible. The /etc/tftpaccess.ctl file should be writable only by root. Although the new /etc/tftpaccess.ctl mechanism provides a very general capability, the CERT/CC strongly recommends that sites keep this control file simple. For example, the following tftpaccess.ctl file is all that is necessary to support IBM X terminals: # /etc/tftpaccess.ctl # By default, all files are restricted if /etc/tftpaccess.ctl exists. # Allow access to X terminal files. allow:/usr/lpp/x_st_mgr/bin NOTE: Be CERTAIN to create the /etc/tftpaccess.ctl file. If it does not exist then all world-readable files are accessible as in the current version of tftpd. Installation Instructions: 1. Create an appropriate /etc/tftpaccess.ctl file. 2. From the directory containing the new tftpd module, issue the following commands as root. # chmod 644 /etc/tftpaccess.ctl # chown root.system /etc/tftpaccess.ctl # mv /etc/tftpd /etc/tftpd.old # cp tftpd /etc # chmod 755 /etc/tftpd # chown root.system /etc/tftpd # refresh -s inetd =========================================================================== /usr/ucb/rdist Vulnerability --------------------------------------------------------------------------- Information concerning a vulnerability in /usr/ucb/rdist (the location of rdist may vary depending on the operating system). This vulnerability is present in possibly all versions of rdist. Vendors responding with patches are listed below. Additionally, some vendors who do not include rdist in their operating systems are identified. Operating systems from vendors not listed in either of the two categories below will probably be affected and the CERT/CC has proposed a workaround for those systems. VENDORS THAT DO NOT SHIP rdist (Note: Even though these vendors do not ship rdist, it may have been added later (for example, by the system administrator). It is also possible that vendors porting one of these operating systems may have added rdist. In both cases corrective action must be taken.) Amdahl AT&T System V Data General DG/UX for AViiON Systems VENDORS PROVIDING PATCHES Cray Research, Inc. UNICOS 6.0/6.E/6.1 Field Alert #132 SPR 47600 For further information contact the Support Center at 1-800-950-CRAY or 612-683-5600 or e-mail support@crayamid.cray.com. NeXT Computer, Inc. NeXTstep Release 2.x A new version of rdist may be obtained from your authorized NeXT Support Center. If you are an authorized support center, please contact NeXT through your normal channels. NeXT also plans to make this new version of rdist available on the public NeXT FTP archives. Silicon Graphics IRIX 3.3.x/4.0 (fixed in 4.0.1) Patches may be obtained via anonymous ftp from sgi.com in the sgi/rdist directory. Sun Microsystems, Inc. SunOS 4.0.3/4.1/4.1.1 Patch ID 100383-02 Patches may be obtained via anonymous ftp from ftp.uu.net or from local Sun Answer Centers worldwide. All trademarks are the property of their respective holders. --------------------------------------------------------------------------- I. Description A security vulnerability exists in /usr/ucb/rdist that can be used to gain unauthorized privileges. Under some circumstances /usr/ucb/rdist can be used to create setuid root programs. II. Impact Any user logged into the system can gain root access. III. Solution A. If available, install the appropriate patch provided by your operating system vendor. B. If no patch is available, restrict the use of /usr/ucb/rdist by changing the permissions on the file. # chmod 711 /usr/ucb/rdist