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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2002.329 -- AIX Security Alert Summary OpenSSH Vulnerabilities in Challenge Response Handling 3 July 2002 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: OpenSSH 2.3.1p1 to 3.3 Vendor: IBM Operating System: AIX with the Linux Affinity Toolkit Impact: Root Compromise Execute Arbitrary Code/Commands Denial of Service Access Required: Remote Ref: AL-2002.05 AA-2002.05 ESB-2002.308 Comments: This advisory contains the response from IBM on the recent OpenSSH Vulnerabilities. It is an update to the summary information provided in ESB-2002.291. - --------------------------BEGIN INCLUDED TEXT-------------------- This file contains summary information on AIX security alerts published by the Computer Emergency Response Team (CERT), and the IBM Emergency Response Team (ERS). The full text of these alerts can be obtained from this mail server by requesting the 'CERT' and 'ERS' files. This information (and more) is available from CERT and ERS directly on the world-wide web at the following URLs: CERT: http://www.cert.org/ ERS: http://www.ers.ibm.com/ In order to keep the size of this file reasonable, it contains only advisories for the current year.. You can obtain a list of previous advisories either from the above URLs, or by requesting one of the "Security_YYYY" documents from this mail server. The fixes mentioned in this document, when available, can be obtained from Electronic Fix Distribution at the following URL: http://techsupport.services.ibm.com/server/fixes The 'Security_APARs' document on this mail server contains a list of security related APARs. =============================================================================== =============================================================================== CERT Advisory CA-2002-18 OpenSSH Vulnerabilities in Challenge Response Handling There are two related vulnerabilities in the challenge response handling code in OpenSSH versions 2.3.1p1 through 3.3. They may allow a remote intruder to execute arbitrary code as the user running sshd (often root). The first vulnerability affects OpenSSH versions 2.9.9 through 3.3 that have the challenge response option enabled and that use SKEY or BSD_AUTH authentication. The second vulnerability affects PAM modules using interactive keyboard authentication in OpenSSH versions 2.3.1p1 through 3.3, regardless of the challenge response option setting. Additionally, a number of other possible security problems have been corrected in OpenSSH version 3.4. IBM's AIX operating system does not ship with OpenSSH; however, OpenSSH is available for installation on AIX via the Linux Affinity Toolkit. The version included on the CD containing the Toolkit is vulnerable to the latest discovered vulnerability discussed here as is the version of OpenSSH available for downloading from the IBM Linux Affinity website. Anyone running this version is advised to follow the recommendations above to limit their vulnerability. We working with the changes for version 3.4 and will have a new package availble for download as soon as possible. When available the new packages can be downloaded from: http://www6.software.ibm.com/dl/aixtbx/aixtbx-p This site contains Linux Affinity applications containing cryptographic algorithms, and new users of this site are asked to register first. =============================================================================== =============================================================================== - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the original authors to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 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 member emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBPSMivCh9+71yA2DNAQEebwP/WomfvIL+s8IiK7xuJUG8DDrfT/9E7LjH fr3Yf5khzU+/Q9EqbRAIw1NecuykanXgvw7dThZp+j+bQqqHmc9jGSqKD5J/F8W+ eFN7bQTFnraqwqGUb7QTUEYB4Laq//+QgyMU8IuhrMhMSgTdHa09I1Qcqk24lvuu lAINZ7wn01c= =DmS+ -----END PGP SIGNATURE-----