<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bulletin 94-34 Release date: 15 November 1994, 12:15 PM EST SUBJECT: A security vulnerability in DECnet/OSI which if exploited, could allow valid users to gain unauthorized system privileges (expanded user privileges). SUMMARY: Digital Equipment Corporation's Software Security Response Team (SSRT) has identified vulnerabilities in DECnet/OSI for OpenVMS AXP and VAX/VMS platforms running OpenVMS utilizing the DECnet/OSI products listed herein. BACKGROUND: Digital Equipment Corporation has discovered the existence of security vulnerabilities in the DECnet-VAX version 5.4 extensions; DECnet/OSI version 2.0, 2.0A and 5.7 for OpenVMS AXP; DECnet/OSI for OpenVMS for VAX version 5.5, 5.6, 5.6A, 5.6B, 5.7, and 5.7A. IMPACT: Security vulnerabilities exist where, under certain circumstances users privileges may be expanded. RECOMMENDED SOLUTION: --------- Begin Software Security Response Team (SSRT) Bulletin ---- PRODUCT: The following products are affected: o DECnet-VAX, Version 5.4 Extensions o DECnet/OSI Version 2.0 for OpenVMS AXP o DECnet/OSI Version 2.0A for OpenVMS AXP o DECnet/OSI Version 5.7 for OpenVMS AXP o DECnet/OSI for OpenVMS VAX, Version 5.5 o DECnet/OSI Version 5.6 for OpenVMS VAX o DECnet/OSI Version 5.6A for OpenVMS VAX o DECnet/OSI Version 5.6B for OpenVMS VAX o DECnet/OSI Version 5.7 for OpenVMS VAX o DECnet/OSI Version 5.7A for OpenVMS VAX SYMPTOM: User privileges may be expanded under certain circumstances. This potential vulnerability can be removed by installing one of the following software updates or ECOs available from Digital: Software update: ---------------- DECnet/OSI Version 5.8 for OpenVMS AXP DECnet/OSI Version 5.8 for OpenVMS VAX ECO Software version: number CSCPAT number ----------------- ------ ------------- DECnet/OSI Version 5.6B for OpenVMS VAX 10 CSCPAT_0597 V1.1 DECnet/OSI Version 5.7 for OpenVMS AXP 02 CSCPAT_0615 V1.1 DECnet/OSI Version 5.7A for OpenVMS VAX 07 CSCPAT_0618 V1.0 Engineering ECO References: CSCPAT_0597 V1.1 = DNVOSIB_ECO10056 CSCPAT_0615 V1.1 = DNVOSIAXP_ECO02057 CSCPAT_0618 V1.0 = DNVOSIA_ECO07057 If you are unable to install one of the above listed updates or ECOs, or if there is no ECO available for the version of DECnet that you are currently running, see the work around described later. Execute the following command to determine which version of DECnet you are currently running: $ WRITE SYS$OUTPUT F$GETSYI("DECNET_VERSION") If "00040100" or "00040200" is displayed then DECnet-VAX, Version 5.4 Extensions is installed. If the "version" begins with "0005", it means that DECnet/OSI is installed. Use the following command to find the version number: $ MCR NCL SHOW IMPLEMENTATION and look for the line beginning with "Version =". For example: $ WRITE SYS$OUTPUT F$GETSYI("DECNET_VERSION") 00050300 $ MCR NCL SHOW IMPLEMENTATION Node 0 at 1994-08-24-16:29:38.991+02:00I1.690 Characteristics Implementation = { [ Name = VMS , Version = "V6.1 " ] , [ Name = DECnet-OSI for OpenVMS , Version = "DECnet-OSI for OpenVMS Version V5.7 14-JAN-1994..." ] } Therefore, DECnet/OSI Version 5.7 for OpenVMS (VAX) is running on this particular machine. WORKAROUND: If you are unable to install one of the software updates or ECOs listed previously, we strongly recommend that you de-install the Common Trace Facility User Interface image (SYS$SYSTEM:CTF$UI.EXE) from memory. Execute the following command to determine if this image is installed on your system: $ INSTALL LIST SYS$SYSTEM:CTF$UI.EXE The following output is displayed if the image is installed: DISK$OPENVMS061:.EXE CTF$UI;5 Prv Execute the following command to de-install the image from memory. Note that you require the privilege CMKRNL to do this. $ INSTALL REMOVE SYS$SYSTEM:CTF$UI.EXE In addition to de-installing the image from memory, steps should be taken to ensure that the image is not (re-)installed during a subsequent machine reboot, or when the Common Trace Facility startup command file executed. To do this, edit the Common Trace Facility startup command file (SYS$COMMON:[SYSMGR]CTF$STARTUP.COM) and search for the following text: F$FILE_ATTRIBUTES("SYS$SYSTEM:CTF$UI.EXE Comment out the code that installs the image into memory. For example: Before: $ IF .NOT. F$FILE_ATTRIBUTES("sys$system:ctf$ui.exe","KNOWN") - THEN install create sys$system:ctf$ui.exe - /privileges=(sysnam,altpri,tmpmbx,syslck,sysgbl,prmgbl,netmbx, - world,pswapm,prmmbx,bypass,cmkrnl) After: $! IF .NOT. F$FILE_ATTRIBUTES("sys$system:ctf$ui.exe","KNOWN") - $! THEN install create sys$system:ctf$ui.exe - $! /privileges=(sysnam,altpri,tmpmbx,syslck,sysgbl,prmgbl,netmbx, - $! world,pswapm,prmmbx,bypass,cmkrnl) Be aware that de-installing the image from memory means that non-privileged users can no longer use the Common Trace Facility User Interface START and STOP commands. This is the case even if the NET$TRACE identifiers have been granted to the user account. The START and STOP commands can now only be executed from a privileged account. AVAILABILITY: If you have a software service or warranty contract, you can obtain the required ECO or software update through your regular Digital support channels. --------- End Software Security Response Team (SSRT) Bulletin ------ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ASSIST is an element of the Defense Information Systems Agency (DISA), Center for Information Systems Security (CISS), that provides service to the entire DoD community. Constituents of the DoD with questions about ASSIST or computer security security issues, can contact ASSIST using one of the methods listed below. Non-DoD organizations/institutions, contact the Forum of Incident Response and Security Teams (FIRST) representative. 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