-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =============================================================================== >> CERT-NL, 01-Mar-2000 << >> All CERT-NL information has been moved to http://cert.surfnet.nl. Links << >> to CERT-NL information contained in this advisory are therefore outdated. << >> << >> CERT-NL also has stopped the CERT-CC-Mirror service. Due to this the << >> links to the CERT-CC mirror are obsolete. Visit the CERT-CC site for the << >> complete CERT-CC advisory texts: http://www.cert.org << =============================================================================== =============================================================================== Security Advisory CERT-NL =============================================================================== Author/Source : Rene Ritzen Index : S-97-25 Distribution : World Page : 1 Classification: External Version: 1 Subject : SGI IRIX login LOCKOUT parameter Vuln. Date : 11-apr-97 =============================================================================== ******* ATTENTION: This advisory has abusively distributed as S-97-24, which already was issued. To prevent double numbering this one has been renumbered to S-97-25! ******* By courtesy of AUSCERT, the Australian CERT, we received information on a vulnerability in SGI IRIX login LOCKOUT parameter. This information is made publicly available by AUSCERT advisory AA-97.12, dated 10-apr-97 CERT-NL recommends that sites apply the steps outlines in Section 3. Keywords: login LOCKOUT parameter ========================================================================== AA-97.12 AUSCERT Advisory SGI IRIX login LOCKOUT parameter Vulnerability 10 April 1997 Last Revised: -- - - - - --------------------------------------------------------------------------- AUSCERT has received information that a vulnerability exists in the login program when the LOCKOUT parameter in /etc/default/login is set to a number greater than zero. This vulnerability is known to be present in IRIX 5.3 and 6.2. Other versions of IRIX may also be vulnerable. This vulnerability may allow users to create arbitrary or corrupt certain files on the system. Exploit information involving this vulnerability has been made publicly available. At this stage, AUSCERT is unaware of any official vendor patches. AUSCERT recommends that sites apply the workaround given in Section 3 until vendor patches are made available. This advisory will be updated as more information becomes available. - - - - --------------------------------------------------------------------------- 1. Description Under the IRIX operating system, there is a file /etc/default/login which contains default security logging configuration options. If the parameter LOCKOUT is included in this file, and is set to a value greater than zero, it causes accounts to be locked after a specified number of consecutive unsuccessful login attempts by the same user. When LOCKOUT is enabled users may be able to create arbitrary or corrupt certain files on the system, due to an inadequate check in the login verification process. Sites can determine if this functionality is enabled by using the command: % grep '^LOCKOUT' /etc/default/login LOCKOUT=3 If the number on the same line as LOCKOUT is greater than zero the vulnerability may be exploited. Information involving this vulnerability has been made publicly available. Silicon Graphics Inc. has informed AUSCERT that they are investigating this vulnerability. 2. Impact Users may create arbitrary or corrupt certain files on the system. 3. Workarounds/Solution AUSCERT recommends that sites prevent the exploitation of this vulnerability by immediately applying the workaround given in Section 3.1. Currently there are no vendor patches available that address this vulnerability. AUSCERT recommends that official vendor patches be installed when they are made available. 3.1 Disable the LOCKOUT parameter To prevent the exploitation of the vulnerability described in this advisory, AUSCERT recommends that the functionality provided with the LOCKOUT parameter be disabled. The LOCKOUT parameter can be disabled by editing /etc/default/login and commenting out the line containing the LOCKOUT parameter. The comment character for /etc/default/login is "#". Note that after applying this workaround, accounts will not be automatically locked using the LOCKOUT parameter functionality. - - - - --------------------------------------------------------------------------- AUSCERT thanks to Alan J Rosenthal from The University of Toronto and Silicon Graphics Inc. for their assistance in this matter. - - - - --------------------------------------------------------------------------- The AUSCERT team have made every effort to ensure that the information contained in this document is accurate. However, the decision to use the information described is the responsibility of each user or organisation. The appropriateness of this document for an organisation or individual system should be considered before application in conjunction with local policies and procedures. AUSCERT takes no responsibility for the consequences of applying the contents of this document. If you believe that your system has been compromised, contact AUSCERT or your representative in FIRST (Forum of Incident Response and Security Teams). AUSCERT is located at The University of Queensland within the Prentice Centre. AUSCERT is a full member of the Forum of Incident Response and Security Teams (FIRST). AUSCERT maintains an anonymous FTP service which is found on: ftp://ftp.auscert.org.au/pub/. This archive contains past SERT and AUSCERT Advisories, and other computer security information. AUSCERT also maintains a World Wide Web service which is found on: http://www.auscert.org.au/. Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 4477 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AUSCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. Postal: Australian Computer Emergency Response Team Prentice Centre Brisbane Qld. 4072. AUSTRALIA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Revision History ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ============================================================================== CERT-NL is the Computer Emergency Response Team for SURFnet customers. SURFnet is the Dutch network for educational, research and related institutes. CERT-NL is a member of the Forum of Incident Response and Security Teams (FIRST). All CERT-NL material is available under: http://cert.surfnet.nl/ In case of computer or network security problems please contact your local CERT/security-team or CERT-NL (if your institute is NOT a SURFnet customer please address the appropriate (local) CERT/security-team). CERT-NL is one/two hour(s) ahead of UTC (GMT) in winter/summer, i.e. UTC+0100 in winter and UTC+0200 in summer (DST). Email: cert-nl@surfnet.nl ATTENDED REGULARLY ALL DAYS Phone: +31 302 305 305 BUSINESS HOURS ONLY Fax: +31 302 305 329 BUSINESS HOURS ONLY Snailmail: SURFnet bv Attn. CERT-NL P.O. Box 19035 NL - 3501 DA UTRECHT The Netherlands NOODGEVALLEN: 06 22 92 35 64 ALTIJD BEREIKBAAR EMERGENCIES : +31 6 22 92 35 64 ATTENDED AT ALL TIMES CERT-NL'S EMERGENCY PHONENUMBER IS ONLY TO BE USED IN CASE OF EMERGENCIES: THE SURFNET HELPDESK OPERATING THE EMERGENCY NUMBER HAS A *FIXED* PROCEDURE FOR DEALING WITH YOUR ALERT AND WILL IN REGULAR CASES RELAY IT TO CERT-NL IN AN APPROPRIATE MANNER. CERT-NL WILL THEN CONTACT YOU. =============================================================================== -----BEGIN PGP SIGNATURE----- Version: PGP 6.5.1i iQA/AwUBOL6IVDSYjBqwfc9jEQIqvACfYseUfc8a2YLg68BC5N9VWZVz1fgAoMPp Kia9A8vNH3TXvCWfxY+xZClF =DGR8 -----END PGP SIGNATURE-----