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security advisorymoderatelocal privilege escalation

SUSE 7.1: SA-2001:17 Moderate: Cron Local Escalation Threat

It may be possible to execute arbitrary commands as root.. ______________________________________________________________________________ SuSE Security Announcement Package: cron-3.0.1-296 Announcement-ID: SuSE-SA:2001:17 Date: Tuesday, May 15th, 2001 14:30:00 CEST Affected SuSE versions: 7.1 Vulnerability Type: local privilege escalation Severity (1-10): 7 SuSE default package: yes Other affected systems: All UN*X systems using this package Content of this advisory: 1) security vulnerability resolved: crontab problem description, discussion, solution and upgrade information 2) pending vulnerabilities, solutions, workarounds 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information The crontab program is running setuser-id root and invokes the editor specified in the EDITOR environment variable, usually vi. If crontab discovers that the format of the edited file is incorrect, it executes the editor again but fails to drop its root privileges before. Therefore it is possible to execute arbitrary commands as root. Sebastian Krahmer has found the bug. It has been fixed by properly dropping the privileges before executing the editor. A possible temporary workaround is to remove the suid bit of the /usr/bin/crontab program: chmod -s /usr/bin/crontab. If you change the mode, you should also do so in the files /etc/permissions*. A permanent solution for the problem is to update the cron package from our ftp server. Download the update package from locations desribed below and install the package with the command `rpm -Uhv file.rpm'. The md5sum for each file is in the line below. You can verify the integrity of the rpm files usingthe command `rpm --checksig --nogpg file.rpm', independently from the md5 signatures below. i386 Intel Platform: SuSE-7.1 b51f3331fff5dac8474a51a1e7d22454 source rpm: 495f7f5df30d28a0c6b078a9773fc799 Sparc Platform: SuSE-7.1 4db292d0276badc0ae58fd6aeaab64c0 source rpm: 16facdbbce03d43fa05d540b810d8636 AXP Alpha Platform: The SuSE-7.1 AXP-Alpha Edition does not suffer from this problem. PPC Power PC Platform: SuSE-7.1 589e8575bbbee29a07319f5c5ada9bcc source rpm: ff747e2aee85a53e3a30827b33383a7d ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: - The man program running setuser-id 'man' suffers from format string and bufferoverflow bugs. Updates are currently being built. ______________________________________________________________________________ 3) standard appendix: SuSE runs two security mailing lists to which any interested party may subscribe: This email address is being protected from spambots. You need JavaScript enabled to view it. - general/linux/SuSE security discussion. All SuSE security announcements are sent to this list. To subscribe, send an email to . This email address is being protected from spambots. You need JavaScript enabled to view it. - SuSE's announce-only mailing list. Only SuSE's security annoucements are sent to this list. To subscribe, send an email to . For general information or the frequently asked questions (faq) send mail to: or respectively. ============================================== SuSE's security contact is . ============================================== Regards, Sebastian Krahmer ______________________________________________________________________________ The information in this advisory may be distributed or reproduced, provided that the advisory is not modified inany way. SuSE GmbH makes no warranties of any kind whatsoever with respect to the information contained in this security advisory. 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A local privilege escalation issue in SuSE's cron poses risks. Update immediately to ensure system integrity and security.. local Privilege Escalation, SuSE Security Announcement, Cron Package Update. . Severity: Important. LinuxSecurity.com Team

May 15, 2001 •Important SuSE