-----BEGIN PRIVACY-ENHANCED MESSAGE----- Proc-Type: 4,MIC-CLEAR Content-Domain: RFC822 Originator-Certificate: MIICozCCAgwCAREwDQYJKoZIhvcNAQECBQAwgYYxC zAJBgNVBAYTAlVTMSswKQYDVQQKEyJEZWZlbnNlIEluZm9ybWF0aW9uIFN5c3Rlb XMgQWdlbmN5MTAwLgYDVQQLEydDZW50ZXIgZm9yIEluZm9ybWF0aW9uIFN5c3Rlb XMgU2VjdXJpdHkxGDAWBgNVBAsTD0NvdW50ZXJtZWFzdXJlczAeFw05MzEyMDkxO DU5MTZaFw05NTEyMDkxODU5MTZaMIGxMQswCQYDVQQGEwJVUzErMCkGA1UEChMiR GVmZW5zZSBJbmZvcm1hdGlvbiBTeXN0ZW1zIEFnZW5jeTEwMC4GA1UECxMnQ2Vud GVyIGZvciBJbmZvcm1hdGlvbiBTeXN0ZW1zIFNlY3VyaXR5MRgwFgYDVQQLEw9Db 3VudGVybWVhc3VyZXMxEzARBgNVBAsTCk9wZXJhdGlvbnMxFDASBgNVBAMTC1Bld GUgSGFtbWVzMIGaMAoGBFUIAQECAgQAA4GLADCBhwKBgQDFFJkcaDOuS+6Ai2vmT bwY6JRbhdzPsl6X60hnXruOw2WvrAhc8BTFB+id75m3M55i+Th6MxWH20QHyQq5u yVghOu/s37OxIrj7irNPjtUdPv8b2m4hNGEW53QH6GmXkxLmgLzOhookpoYPC+uw 2MzibDnleVI50d2m//XsWs7hwIBAzANBgkqhkiG9w0BAQIFAAOBgQDHH6CmBoyWU zPlqVnEWYKIBsifqdTJzkKfnoST7NDRIakUP49FP86Cyy1+2AKpUCWaxjq+wGHCH RCNFCCrOwdC9z8XwJal/c69ml6eLRhOoX77ANndpU9E5+eHxP+6Ute6lc63K7+Lz 5xOULjmgaMmKDkTXveVcQO6R2CTY37vcA== Issuer-Certificate: MIICNTCCAZ4CASIwDQYJKoZIhvcNAQECBQAwRDELMAkGA 1UEBhMCVVMxCzAJBgNVBAgTAk1EMSgwJgYDVQQKEx9UcnVzdGVkIEluZm9ybWF0a W9uIFN5c3RlbXMgUENBMB4XDTk0MDIyNTE0NDkxMloXDTk0MDMwNzE0NDkxMlowg YYxCzAJBgNVBAYTAlVTMSswKQYDVQQKEyJEZWZlbnNlIEluZm9ybWF0aW9uIFN5c 3RlbXMgQWdlbmN5MTAwLgYDVQQLEydDZW50ZXIgZm9yIEluZm9ybWF0aW9uIFN5c 3RlbXMgU2VjdXJpdHkxGDAWBgNVBAsTD0NvdW50ZXJtZWFzdXJlczCBmjAKBgRVC AEBAgIEAAOBiwAwgYcCgYEA19l6BN7iTGYEU61qJETIjBh3iAeHzoL8sZ5KwFRZD S/a1KnYlD1zJHR/KeQCOBWW2HzX43TFLCNGU7UD9i6m8AymLe5IJf/bGh0Rne7Jd Q1GAOLw7/J4hE57IMbGETZpzeU1D9IYxiERRNio/oa422lUlS9JZHLA5jaPNcUrX P8CAQMwDQYJKoZIhvcNAQECBQADgYEApkliqAdudoOxvOFmQkOZbSgtlpn61VcNC R7azDNJa2ulevaebptwSTs2OvMeuR/J0Ez4TC7XrJXLVjI5huRAqc+EWGRpZYRMa CARZyE7gGYjUqS7DIQazfskeWiB8zheyW5tCVn+jnB09AZXtgbM6qRjyqrmSdCpg CtfgazIKqI= Issuer-Certificate: MIIB8jCCAVsCAQEwDQYJKoZIhvcNAQECBQAwRDELMAkGA 1UEBhMCVVMxCzAJBgNVBAgTAk1EMSgwJgYDVQQKEx9UcnVzdGVkIEluZm9ybWF0a W9uIFN5c3RlbXMgUENBMB4XDTkzMDUyODE3MTEyN1oXDTk1MDUyODE3MTEyN1owR DELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAk1EMSgwJgYDVQQKEx9UcnVzdGVkIEluZ m9ybWF0aW9uIFN5c3RlbXMgUENBMIGaMAoGBFUIAQECAgQAA4GLADCBhwKBgQDbL xaRlS3u54yyRgVDI5dcE9nlasL8fJqOGlyo7xH2FZnr3kUfsFj7OGiYsr6UbvqwK nyfMIRUrXDUa64leGmft3SK27psDUHOynRSCc40d/HrDf810U5tnTamBKUIMqivK 4GoL0tMRA1eX6hALAvLLgK1HbnwZAo6GqQGW8CIJQIBAzANBgkqhkiG9w0BAQIFA AOBgQDBp5aC6oV6IuFi8JCctq57bew604HHNllgjjp7zdXafq6jctRg2g91k/yFW h19bJC/tNrb0WVwuZOs5L/FToPMNIIHzaW/YSROBmyhTDYaKHZGj0P1+iNjMbHt9 dm1QEHGIfKgBwFidItnOa74DfkXdijlPRnr/+E2Ib6PM+hEfQ== MIC-Info: RSA-MD5,RSA,YXPTDbdS2oG55/dLEoEPj8qpTTD9nwpefTNHqxw9s32 rDDqs9eLNePlUP4+GLMGFxbqnL0v7WGbQVx0lwaYs1wLtIXzYx8owYGfyCCUmDvU XEzWUUyRGf0jKrkY6ScMZvk14is2wZrG9F2bgIjo30QY/6o19Mz30G/cNXGq02pM = <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bulletin 95-06 Release date: 22 February, 1995, 10:00 AM EST (GMT -4) SUBJECT: Telnet Encryption Vulnerability. SUMMARY: There is a vulnerability in Berkeley Telnet clients that support encryption and Kerberos V4 authentications. This vulnerability substantially reduces the effectiveness of the encryption. BACKGROUND: This vulnerability involves a serious security problem in the Berkeley Telnet clients that provide support for the experimental Telnet encryption option using the Kerberos V4 authentication. All known released versions of the BSD Telnet that support Kerberos V4 authentication and encryption are affected. IMPACT: Anyone who can access and read packets that make up the encrypted Telnet session can easily decrypt the session. This vulnerability could possibly be exploited by an intruder to view Telnet sessions captured by a network sniffer. RECOMMENDED SOLUTION: Obtain and install the appropriate patch according to the instructions included with the patch. Listed below is a summary of information provided by vendors regarding the status of the vulnerability and fixes for their systems. More complete information, including how to obtain patches, is printed in Appendix A of this bulletin. Vendor or Source Status - ---------------- ------------ Berkeley SW Distribution (BSD) source-code patch available from Berkeley; also in Appendix B of this advisory Data General Corporation not affected by the vulnerability FTP Software, Inc. patch available Harris NightHawk System not affected by the vulnerability Hewlett-Packard Company not affected by the vulnerability Nat'l. Center for Supercomputer upgrade available Applications (NCSA) Open Software Foundation not affected by the vulnerability The Santa Cruz Operation, Inc. (SCO) not affected by the vulnerability Sun Microsystems, Inc. not affected by the vulnerability If you have an encrypting Telnet from some other vendor, please contact ASSIST or that vendor for information regarding how to get a fixed version. ASSIST would like to thank the CERT Coordination for information contained in this 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) (FIRST) representative. To obtain a list of FIRST member organizations and their constituencies send an email to docserver@first.org with an empty "subject" line and a message body containing the line "send first-contacts". ASSIST Information Resources: To be included in the distribution list for the ASSIST bulletins, send your Milnet (Internet) e-mail address to assist-request@assist.mil. Back issues of ASSIST bulletins, and other security related information, are available from the ASSIST BBS at 703-756-7993/1154 DSN 289-7993/1154, and through anonymous FTP from assist.mil (IP address 199.211.123.11). Note: assist.mil will only accept anonymous FTP connections from Milnet addresses that are registered with the NIC or DNS. ASSIST Contact Information: PHONE: 800-357-4231 (or 703-756-7974 DSN 289), duty hours are 06:00 to 22:30 EDT (GMT -4) Monday through Friday. During off duty hours, weekends and holidays, ASSIST can be reached via pager at 800-791- 4857. The page will be answered within 30 minutes, however if a quicker response is required, prefix the phone number with "999". ELECTRONIC MAIL: Send to assist@assist.mil. ASSIST BBS: Leave a message for the "sysop". Privacy Enhanced Mail (PEM): ASSIST uses PEM, a public key encryption tool, to digitally sign all bulletins that are distributed through e-mail. The section of seemingly random characters between the "BEGIN PRIVACY-ENHANCED MESSAGE" and "BEGIN ASSIST BULLETIN" contains machine-readable digital signature information generated by PEM, not corrupted data. PEM software for UNIX systems is available from Trusted Information Systems (TIS) at no cost, and can be obtained via anonymous FTP from ftp.tis.com (IP 192.94.214.96). Note: The TIS software is just one of several implementations of PEM currently available and additional versions are likely to be offered from other sources in the near future. Reference herein to any specific commercial product, process, or service by trade name, trademark manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by ASSIST. The views and opinions of authors expressed herein shall not be used for advertising or product endorsement purposes. Appendix A: Vendor Information Current as of February 16, 1995 Below is information from vendors who have patches available or upcoming, along with names of vendors who have reported that their products do not have the problem. If you have an encrypting Telnet from a vendor who is not listed, please contact ASSIST or that vendor for information regarding how to get a fixed version. Vendor or Source Status - ---------------- ------------ Berkeley SW Distribution (BSD) source-code patch available from Berkeley; also in Appendix B of this advisory Data General Corporation not affected by the vulnerability FTP Software, Inc. patch available Harris NightHawk System not affected by the vulnerability Hewlett-Packard Company not affected by the vulnerability Nat'l. Center for Supercomputer upgrade available Applications (NCSA) Open Software Foundation not affected by the vulnerability The Santa Cruz Operation, Inc.(SCO) not affected by the vulnerability Sun Microsystems, Inc. not affected by the vulnerability PATCH INFORMATION - ------------- Berkeley Software Distribution (BSD) A source-code patch, along with the domestic version of the most recently released Telnet sources from Berkeley, are available by anonymous FTP from: net-dist.mit.edu:/pub/telnet/telnet.patch MD5 65d56befe3d0f1699d38de5509552578 There is also a PGP ASCII signature file for the patch in: net-dist.mit.edu:/pub/telnet/telnet.patch.sig This patch can also be found in Appendix B. Note: Do not calculate a checksum for Appendix B alone. It will not match the checksum of the FTP version of the patch because the tabs in the FTP copy have been replaced with blank spaces in the Appendix B copy. - ------------- FTP Software, Inc. Customers of FTP Software with an encrypting telnet (provided in the PC/TCP or OnNet packages) should call the FTP technical support line at 1-800-282-4387 and ask for the "tn encrypt patch". - ------------- National Center for Supercomputer Applications (NCSA) Users of NCSA Telnet should upgrade to the NCSA Telnet 2.6.1d7, AND install the appropriate Kerberos plug-in which are available by anonymous FTP from ftp.ncsa.uiuc.edu. Upgrade: /Mac/Telnet/Telnet2.6/prerelease/d7/Telnet2.6.1d7(68K).sit.hqx MD5 b34b9fda59421b3b83f8df08a83f83b5 /Mac/Telnet/Telnet2.6/prerelease/d7/Telnet2.6.1d7(fat).sit.hqx MD5 877add7c3d298111889fc3f2f272ce6f Kerberos plug-ins: /Mac/Telnet/Telnet2.6/prerelease/AuthMan.plugin.1.0b1.hqx MD5 df727eae184b22125f90ef1a31513fd4 /Mac/Telnet/Telnet2.6/prerelease/Kerberos_Telnet_plugin.sit.hqx MD5 dbda691efe9038648f234397895c734d Questions regarding NCSA Telnet should be directed to mactel@ncsa.uiuc.edu ......................................................................... Appendix B: Patch for Vulnerability in Telnet Encryption Option Current as of February 16, 1995 Index: auth.c =================================================================== RCS file: /mit/krb5/.cvsroot/src/appl/telnet/libtelnet/auth.c,v retrieving revision 5.5 retrieving revision 5.7 diff -u -r5.5 -r5.7 - --- auth.c 1994/08/18 21:06:45 5.5 +++ auth.c 1994/11/08 04:39:02 5.7 @@ -244,7 +244,7 @@ { register int x; - - if (strcasecmp(type, AUTHTYPE_NAME(0))) { + if (!strcasecmp(type, AUTHTYPE_NAME(0))) { *maskp = -1; return(1); } @@ -260,14 +260,14 @@ int auth_enable(type) - - int type; + char * type; { return(auth_onoff(type, 1)); } int auth_disable(type) - - int type; + char * type; { return(auth_onoff(type, 0)); } @@ -277,15 +277,20 @@ char *type; int on; { - - int mask = -1; + int i, mask = -1; Authenticator *ap; if (!strcasecmp(type, "?") || !strcasecmp(type, "help")) { printf("auth %s 'type'\n", on ? "enable" : disable"); printf("Where 'type' is one of:\n"); printf("\t%s\n", AUTHTYPE_NAME(0)); - - for (ap = authenticators; ap->type; ap++) + mask = 0; + for (ap = authenticators; ap->type; ap++) { + if ((mask & (i = typemask(ap->type))) != 0) + continue; + mask |= i; printf("\t%s\n", AUTHTYPE_NAME(ap->type)); + } return(0); } @@ -293,7 +298,6 @@ printf("%s: invalid authentication type\n", type); return(0); } - - mask = getauthmask(type, &mask); if (on) i_wont_support &= ~mask; else @@ -317,16 +321,22 @@ auth_status() { Authenticator *ap; + int i, mask; if (i_wont_support == -1) printf("Authentication disabled\n"); else printf("Authentication enabled\n"); - - for (ap = authenticators; ap->type; ap++) + mask = 0; + for (ap = authenticators; ap->type; ap++) { + if ((mask & (i = typemask(ap->type))) != 0) + continue; + mask |= i; printf("%s: %s\n", AUTHTYPE_NAME(ap->type), (i_wont_support & typemask(ap->type)) ? "disabled" : "enabled"); + } return(1); } Index: kerberos.c =================================================================== RCS file: /mit/krb5/.cvsroot/src/appl/telnet/libtelnet/kerberos.c,v retrieving revision 5.5 retrieving revision 5.8 diff -u -r5.5 -r5.8 - --- kerberos.c 1994/08/18 21:07:02 5.5 +++ kerberos.c 1994/11/14 21:33:58 5.8 @@ -225,9 +225,10 @@ register int i; des_key_sched(cred.session, sched); - - des_set_random_generator_seed(cred.session); - - des_new_random_key(challenge); - - des_ecb_encrypt(challenge, session_key, sched, 1); + des_init_random_number_generator(cred.session); + des_new_random_key(session_key); + des_ecb_encrypt(session_key, session_key, sched, 0); + des_ecb_encrypt(session_key, challenge, sched, 0); /* * Increment the challenge by 1, and encrypt it for * later comparison. @@ -320,6 +321,11 @@ break; } -----END PRIVACY-ENHANCED MESSAGE-----