=============================================================================== Security Advisory CERT-NL =============================================================================== Author/Source : CERT-NL (Don Stikvoort) Index : S-94-06 Distribution : World Page : 1 Classification: External Version: Final Subject : SunOS /usr/ucb/rdist Vulnerability Date : 18-Mar-94 (plus rdist addendum for non-SunOS systems) =============================================================================== CERT-NL received information on a vulnerability in /usr/ucb/rdist in SunOS 4.1.1 / 4.1.2 / 4.1.3 / 4.1.3c on sun3 and sun4. Concerning non-SunOS systems CERT-NL appended an overview of older information. The vulnerability is being actively exploited, so take care. All honours to CERT/CC as provider of the following information (slightly abridged version): =============================================================================== The CERT Coordination Center has received information concerning a vulnerability in /usr/ucb/rdist in Sun Microsystems, Inc. SunOS 4.1.1, 4.1.2, 4.1.3, and 4.1.3c on all sun3 and sun4 architectures. SunOS 4.1.3_U1, Solaris 2.x, and Solbourne's 4.1B and 4.1C are not vulnerable. This is a Sun specific Advisory. Please reference the 1991 CERT Advisory CA-91:20 "/usr/ucb/rdist Vulnerability" for general information regarding other vendors, plus the corresponding (updated!) vendor status file rdist-patch-status, BOTH APPENDED AT THE END OF THIS ADVISORY. This vulnerability is being actively exploited; please review: CERT-NL Advisory S-94-02 "Ongoing Network Monitoring Attacks". Patches can be obtained from local Sun Answer Centers worldwide as well as through anonymous FTP from: ftp.nic.surfnet.nl in the surfnet/net-security/cert-nl/patches/sun-fixes directory. Information concerning specific patches is outlined below. Please note that Sun sometimes updates patch files. Information regarding these changes ARE documented by Sun and mirrored in the afore mentioned directory. If in doubt please contact Sun. ----------------------------------------------------------------------------- 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 This vulnerability allows a local user to gain root access. III. Solution A. If rdist is not being used, change the permissions on the file. # chmod 700 /usr/ucb/rdist B. Obtain and install the appropriate patches according to the instructions included with the patches. Module Patch ID Filename ---------- --------- --------------- rdist 100383-06 100383-06.tar.Z BSD Checksum = 58984 121 System V Checksum = 9125 241 MD5 Checksum = f8f78ddab19af5efabb9bd66fc8f5c1a ============================================================================== APPENDIX CA-91:20 : ==================== CA-91:20 CERT Advisory October 22, 1991 /usr/ucb/rdist Vulnerability --------------------------------------------------------------------------- The Computer Emergency Response Team/Coordination Center (CERT/CC) has received 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 : see file rdist-patch-status APPENDED BELOW. 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 --------------------------------------------------------------------------- The CERT/CC wishes to thank Casper Dik of the University of Amsterdam, The Netherlands, for bringing this vulnerability to our attention. We would also like to thank the vendors who have responded to this problem. --------------------------------------------------------------------------- =========================================================================== APPENDIX rdist-patch-status : ============================= Rev. 17 Mar 94 I. Vendors that do not include rdist in their operating system distributions: Amdahl AT&T System V Data General DG/UX for AViiON Systems Sequent Computer Systems (note they will begin to ship rdist in February 1992, but it will be the corrected version) II. Vendors providing patches: A. Apollo Domain/OS SR10.3 and SR10.3.5 (Fixed in SR10.4) a88k PD92_P0316 m68k PD92_M0384 HP customers should contact their local response center to obtain patches. B. 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. C. IBM RS/6000 AIX levels 3005, 2006, 2007, and 3.2 apar ix23738 Patches may be obtained by calling Customer Support at 1-800-237-5511. D. MIPS RISCos versions 4.50 through 4.52 (not required for 5.0) Patches are available via anonymous ftp at ftp.mips.com. The file is /pub/rdist.CERT.tar. E. 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. F. 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. G. Solbourne OS/MP 4.1A Patch ID P911121003 H. Sun Microsystems, Inc. SunOS 4.0.3/4.1.1/4.1.2/4.1.3/4.1.3c sun3/sun4 architectures PatchID 100383-06 Patches can be obtained from local Sun Answer Centers worldwide as well as through anonymous FTP from: ftp.nic.surfnet.nl in the surfnet/net-security/cert-nl/patches/sun-fixes directory. ============================================================================== CERT-NL is the Computer Emergency Response Team, located in The Netherlands. CERT-NL is a Full Member of the Forum of Incident Response and Security Teams (FIRST). The constituency of CERT-NL are the SURFnet connected institutions. Past CERT-NL Security Bulletins and other CERT-NL related material can be found on the anonymous FTP server of SURFnet bv: "ftp.nic.surfnet.nl" [192.87.46.3], in the directory "surfnet/net-security/cert-nl/docs/bulletin". This information is also available using email. Send an email saying "help" to "mailserv@nic.surfnet.nl". In case of computer or network security problems please contact CERT-NL or the CERT of your own constituency. Please be aware of the fact that we are one (when DST is in effect two) hour(s) ahead of Universal Time Coordinated (i.e. UTC+0100 (UTC+0200)). Email: cert-nl@surfnet.nl Phone: +31 30 310290 Fax: +31 30 340903 Snailmail: SURFnet bv Attn. CERT-NL P.O. Box 19035 NL - 3501 DA UTRECHT The Netherlands A 7 * 24 hours phone number is available to SURFnet SSC's and FIRST members on request. ==============================================================================