Date: 05 May 1994 21:21:55 -0400 From: Pete Hammes Subject: ASSIST 94-12 To: assist-bulletin@assist.ims.disa.MIL Content-transfer-encoding: 7BIT -----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,aNcs0nPvUCOmQyHmgfYLZf7kyeDlZKuQJzCBYS3cE6n RrNJjmj/KxK585jbowxYtvAHUiApDTU6nI8MYpYR42nIkQC9qLGmHs7+KPvd/jfI I07nLx/xDVSqmD4md9tZ7S5fz1j03Tkw01P5pc6rWSUtNeiB3oZtDhrYk1x2dHi0 = <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bulletin 94-12 Release date: 5 May 1994, 9:10 PM EDT Subject: FTP daemon (ftpd) vulnerabilities SUMMARY: This bulletin contains information about two vulnerabilities that exist in several ftpd implementations. The first is a vulnerability with the SITE EXEC command feature of ftpd found in versions that support the SITE EXEC feature. The second involves a race condition found in the ftpd implementations listed in the BACKGROUND section of this bulletin. Information about these vulnerabilities has been widely distributed in various forums, and any site running a version of ftpd listed in this bulletin should immediately take steps to upgrade or disable ftpd. Sites using these implementations are vulnerable even if they do not support anonymous FTP. Sites whose ftpd is derived from the DECWRL or wuarchive ftpd code containing the SITE EXEC feature are also at risk. BACKGROUND: There is a vulnerability in the SITE EXEC command feature of ftpd that allows any remote or local user to obtain root access. There is also a vulnerability caused by a race condition in these implementations. Versions known to be vulnerable to these problems are: wuarchive ftpd versions 2.0-2.3 (version 2.2 patched the SITE EXEC problem, but not the race condition) DECWRL ftpd versions prior 5.93 BSDI ftpd version 1.1 prior to patch 5 The SITE EXEC vulnerability affects ftpd only if the SITE EXEC command feature has been explicitly activated at your site. SITE EXEC is not activated by default, and sites that have not enabled this feature are not at risk from this vulnerability. However, since the race condition does not have an easily applied workaround, ASSIST recommends that you upgrade to one of the versions listed below. IMPACT: Anyone (remote or local) can gain root access on a host running a vulnerable FTP daemon. Support for anonymous FTP is not required to exploit this vulnerability. RECOMMENDED SOLUTION: Both of these problems can be eliminated from the affected systems listed below by upgrading to the latest version of ftpd. Be certain to verify the checksum information to confirm that you have retrieved a valid copy. If the upgrade cannot be installed immediately, disable ftpd until the problem is corrected. It is not sufficient to disable anonymous FTP until the upgrade is installed, you must disable ftpd. For wuarchive ftpd, you can obtain version 2.4 via anonymous FTP FTP from wuarchive.wustl.edu, in the "/packages/wuarchive-ftpd" directory. If you are currently running version 2.3, a patch file is available. BSD SVR4 File Checksum Checksum - ----------------- -------- --------- wu-ftpd-2.4.tar.Z 38213 181 20337 362 MD5 Digital Signature --------------------- cdcb237b71082fa23706429134d8c32e BSD SVR4 File Checksum Checksum - ----------------- -------- --------- patch_2.3-2.4.Z 09291 8 51092 16 MD5 Digital Signature --------------------- 5558a04d9da7cdb1113b158aff89be8f For DECWRL ftpd, sites can obtain version 5.93 via anonymous FTP from gatekeeper.dec.com in the "/pub/misc/vixie" directory. BSD SVR4 File Checksum Checksum - ----------------- -------- --------- ftpd.tar.gz 38443 60 1710 119 MD5 Digital Signature --------------------- ae624eb607b4ee90e318b857e6573500 For BSDI systems, patch 005 should be applied to version 1.1 of The BSD/386 software. You can obtain the patch file via anonymous FTP from ftp.bsdi.com in the "/bsdi/patches-1.1" directory. BSD SVR4 File Checksum Checksum MD5 Digital Signature - ----------------- -------- --------- --------------------- BU110-005 35337 272 54935 543 MD5 Digital Signature --------------------- 1f454d4d9d3e1397d1eff0432bd383cf 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. If you are a constituent of the DoD and have any questions about ASSIST or computer security issues, contact ASSIST using one of the methods listed below. If your organization/institution is non-DoD, contact your Forum of Incident Response and Security Teams (FIRST) representative. You can obtain a list of FIRST member organizations and their constituencies by sending email to docserver@first.org with an empty "subject" line and a message body containing the line "send first-contacts". ASSIST INFORMATION RESOURCES: If you would like to be included in the distribution list for these bulletins, send your Milnet (Internet) e-mail address to assist-request@assist.ims.disa.mil. Back issues of ASSIST bulletins, and other security related information, are available from the ASSIST BBS at 703-756-7993/ 1154 DSN 289, and through anonymous FTP from assist.ims.disa.mil (IP address 137.130.234.30). Note: assist.ims.disa.mil will only accept anonymous FTP connections from Milnet addresses that are registered with the NIC or DNS. ASSIST contact information: PHONE: 703-756-7974, DSN 289, duty hours are 06:00 to 22:30 EST Monday through Friday. During off duty hours, weekends, and holidays, ASSIST can be reached via pager at 800-SKY-PAGE (800-759-7243) PIN 2133937. Your page will be answered within 30 minutes, however if a quicker response is required, prefix your phone number with "999". ELECTRONIC MAIL: Send to assist@assist.ims.disa.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: This is not an endorsement by ASSIST of TIS or it's products. 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 products, 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. -----END PRIVACY-ENHANCED MESSAGE-----