KSR[T] Advisory #3: updatedb / crontabs

[ksrt () DEC NET (KSR[T])]

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KSR[T] Website : http://www.dec.net/ksrt
E-mail: ksrt () dec net
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                                                          KSR[T] Advisory #003
                                                          Date:   Aug 05, 1997
                                                          ID #:   lin-cron-003

Operating System(s): Redhat linux 4.1, SuSE Linux 5.0, Slackware 3.3

Affected Program:    updatedb / crontabs

Problem Description: There are numerous problems in the default root crontabs
                     for several flavors of UNIX.  This advisory will contain
                     a brief description of several vulnerabilities that we
                     have discovered.

                     Redhat Linux 4.1:  updatedb contains several security
                     holes.   Updatedb will send the results of a find
                     command string to sort.  Sort will use /tmp to store
                     temp files, and it will follow symbolic links.  A
                     creative attacker can create files in a world writable
                     directory that allows them to control what data will
                     be written to the symbolic link.

                     SuSE Linux 5.0:  makewhatis uses /tmp, this allows
                     attackers to overwrite files as root.  They cannot
                     control the data being written.

                     The system crontab also calls updatedb.

                     check_log_file() contains a SERIOUS security hole that
                     will allow an intruder to write over any file on the
                     system, with whatever he/she wants.  There are numerous
                     other /tmp file problems with the default crontab,
                     it is highly recommended that you upgrade immediately.
                     ( See Patch/Fix section )

                     Slackware 3.3 also comes with a vulnerable version
                     of updatedb installed.

Compromise:          updatedb can allow any local user to execute commands
                     as any user, including root.

                     SuSE's default crontab can allow local users to execute
                     commands as root.

                     makewhatis can allow local users to overwrite/create
                     any file on the system.

Patch/Fix:

Redhat
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This problem was fixed in Redhat 4.2.

S.u.S.E
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Fixes for S.u.S.E. Linux 5.0:
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    ftp://ftp.suse.com/pub/suse_update/S.u.S.E.-5.0/a1/aaa_base.rpm

md5:
1ea3b7c6760b6e8db98b49897ba47ad1  aaa_base.rpm

    ftp://ftp.suse.com/pub/suse_update/S.u.S.E.-5.0/ap1/makewhat.rpm

md5:
e22df292fe878397cbe800ff796c3a0b  makewhat.rpm


Fixes for S.u.S.E. Linux 4.4.1 (should work for older versions too):
--------------------------------------------------------------------

    ftp://ftp.suse.com/pub/suse_update/S.u.S.E.-4.4.1/a1/aaa_base.tgz

md5:
4c0bff940210b83c00564595fd3e35b3  aaa_base.tgz

    ftp://ftp.suse.com/pub/suse_update/S.u.S.E.-4.4.1/ap1/makewhat.tgz

md5:
503e1678dea767bf2cdab04282777c73  makewhat.tgz