From support@us.external.hp.com Wed Mar 13 00:59:34 1996 Date: Wed, 13 Mar 1996 01:02:26 -0800 From: HPSL Mail Service Reply to: support-feedback@us.external.hp.com To: Damien Sorder Subject: RE: send doc HPSBUX9405-010 -------- ## Regarding your request: Send Doc HPSBUX9405-010 The following are the results of your request from the HP SupportLine mail service. =============================================================================== Document Id: [HPSBUX9405-010] Date Loaded: [05-05-94] Description: ftpd: SITE CHMOD / race condition vulnerability =============================================================================== ----------------------------------------------------------------------- HEWLETT-PACKARD SECURITY BULLETIN: #00010, 4 May 94 ******** ADVISORY ONLY ******** ----------------------------------------------------------------------- _______________________________________________________________________ ISSUE #1: Ftpd race condition security problem announced by CIAC,CERT. PLATFORM: All HP-UX systems STATUS: NOT present on HP-UX. ADVICE: Continue to use ftpd distributed with HP-UX. ISSUE #2: HP-UX ftpd man page recommends wrong ownership of ftp home directory. PLATFORM: All HP-UX systems. STATUS: Present on all HP-UX systems. ADVICE: Root should own ftp home directory. _______________________________________________________________________ I. ftpd Race Condition A. Nature of the Problem Recent announcements by CIAC (E-17) and CERT (CA-94:08) warned of a potential danger caused by a race condition in later versions of ftpd. With this problem, certain versions of ftpd would allow unauthorized access to files in the ftp directory structure. (A previous HP Security Bulletin #00007 dealt with the ftp problem caused by SITE EXEC and also discussed in the CIAC and CERT announcments.) B. Status of HP-UX HP-UX ftpd does NOT have this race condition problem, so this security threat does NOT exist. Some HP-UX users may have chosen to run the non-HP version of ftpd available from source archives such as the wuarchive. These ftpds may be vulnerable and these users should heed the CIAC/CERT warnings. C. Recommended Actions HP-UX users should continue to use the ftpd distributed with the release tapes or provided in official HP-UX patches. II. HP-UX ftpd SITE CHMOD Command A. Nature of the Problem The HP-UX ftpd allows an anonymous ftp user to issue a SITE CHMOD command to change the permissions on any file owned by owned by ftp. This could permit unauthorized access of files owned by the ftp user. The ftpd man page provides appropriate recommendations for the permissions and ownership of all the sub-directories, but erroneously recommends that the ~ftp home directory be owned by ftp. This allows an anonymous ftp user to change the permission on the ~ftp home directory, and control (read/modify/delete) any files owned by ftp in the ~ftp home directory. B. Status of HP-UX HP-UX ftpd does support SITE CHMOD, so this potential security vulnerability does exist. C. Recommended Actions The ftpd man page provides correct information except for the ownership of the ftp home directory: it should be owned by root, not ftp. Also, system administrators should be aware that ftp-owned files in ftp-owned directories can be modified by anonymous ftp. While this may be desirable for incoming ftp files (send by an anonymous user), this is probably undesirable for distribution files. For such files, administrators should use root ownership. Appendix A. Contacting CERT 1. For complete details on CERT, use anonymous ftp to retrieve ~pub/cert_faq from cert.org. The advisory mentioned above can be retreived using anonymous ftp to cert.org: it is kept in ~pub/cert_advisories/CA-94:08.ftpd.vulnerabilities. 2. Write to cert@cert.org. 3. Call 1 412-268-7090 (24-hour hotline) Appendix B. Contacting CIAC (US Dept of Energy) 1. Call 510-422-8193 2. Write to ciac@llnl.gov. 3. Subscribe to mailing lists, by sending body text containing: subscribe CIAC-BULLETIN Full_Name Phone_number to ciac-listproc@llnl.gov. ----------------------------------------------------------------------- To subscribe to automatically receive NEW future HP Security Bulletins from the HP SupportLine mail service via electronic mail, send the following in the TEXT PORTION OF THE MESSAGE to support@support.mayfield.hp.com (no Subject is required): subscribe security_info To retrieve the index of all HP Security Bulletins, send the following: send security_info_list To obtain a copy of the HP SupportLine mail service user's guide, send the following to support@support.mayfield.hp.com: send guide.txt For security concerns, write to: security-alert@hp.com -----------------------------------------------------------------------